Figure 7.3: Timeline of cardiac biomarkers after a myocardial infarction.


Figure 7.4: Comparison of audible and inaudible S4 sounds.


Figure 7.5: Hyperacute T-waves associated with an early myocardial infarction.


Figure 7.6: Which leads look at which coronary vessels? LCx = left circumflex, LAD = left anterior descending, RCA = right coronary artery.


Figure 7.7: An ECG showing an anterior wall infarction with the characteristic “tombstoning” of the T-wave.


Figure 7.9: IWMI.


Figure 7.11: Posterior wall MI.


Figure 7.1: Sequences in progression of atherosclerosis.


Figure 6.1: Schematic of ASD showing left–right shunt. Thicker lines indicate the presence of volume overload.


Figure 6.2: Schematic of VSD showing left–right shunt that can lead to volume overload in the RV, LA, LV, and pulmonary circulation. Dotted lines show the recirculation of blood back through the pulmonary circulation. Thicker lines denote volume overload.


Figure 6.3: Coarctation of the aorta (circled).


Figure 6.4: Tetralogy of Fallot with 1) pulmonic stenosis, 2) RV hypertrophy, 3) VSD, and 4) overriding aorta.


Figure 6.5: Schematic of transposition of the great vessels (aorta off of the right, pulmonary artery off of the left) forming two separate, looped circulations.


Figure 6.6: Schematic of PDA with flow from the aorta to the pulmonary artery. Thicker lines denote volume overload.


Figure 6.7: AV Canal with 1) ASD, 2&3) AV valve defects, and 4) VSD.


Figure 6.8: Truncus arteriosus.


Figure 5.1: Normal and abnormal differences in the components of S1 (M1 and T1).


Figure 5.2: Normal splitting of S2 with inspiration.


Figure 4.1: Histological view of the ossification of valve tissue with osteoblast-like cells clustered in the center of the field of view. These cells are responsible for the calcification and consequent stiffening of the valve leaflet.


Figure 4.2: Mitral valve prolapse.


Figure 4.3: Pathophysiology of rheumatic heart disease.


Figure 4.4: Vegetative lesions (in white box) associated with IE.


Figure 4.5: Signs of IE include Janeway lesions (left), Osler nodes (middle), and Roth spots (right).


Figure 4.6: NBTE with small thrombi binding to valve leaflets.


Figure 4.7: Small “wart-like vegetations” in the cords of a valve.


Figure 4.8: Release of inflammatory mediators from neuroendocrine tumors leading to carcinoid heart disease.


Figure 3.1: Potential sources of essential hypertension.


Figure 3.2: Consequences of hypertension.


Figure 2.1: Overly simplified schema of heart failure. Systolic = cannot get the blood out; Diastolic = cannot get the blood in.


Figure 2.2: Calculation for ejection fraction.


Figure 2.3: Pathophysiological sequence of left ventricular failure. Whether through lowered ejection fraction (HFREF, a.k.a. systolic failure) or through poor ventricular filling (heart failure with a normal ejection fraction, or HFNEF, a.k.a. diastolic failure), the end point of pulmonary congestion is the same.


Figure 2.4: Compensatory responses to reduced cardiac output.


Figure 2.5: The effects of volume and pressure overload on the morphology of the heart and cardiac myocytes.


Figure 2.6: Normal myocardial (A) and myocardium exposed to valvular disease (B).


Figure 2.7: Consequences of right- and left-sided heart failure.


Figure 1.1: An ECG of atrial fibrillation showing lack of P-waves and low-amplitude fibrillation waves between QRS complexes.


Figure 1.2: Comparison of atrial arrhythmias, including atrial fibrillation (left), atrial flutter (middle), and multifocal atrial tachycardia (MAT) (right).


Figure 1.3: Atrial flutter — “sawtooth” P-waves with lower frequency than the fibrillation waves of atrial fibrillation.


Figure 1.4: Three distinct P-wave morphologies in a case of MAT.


Figure 1.5: Atrial bigeminy in PAC with ECG complexes appearing in pairs.


Figure 1.6: PVCs have a wider complex and are followed by a compensatory pause.


Figure 1.7: Monomorphic and polymorphic VT.


Figure 1.8: Torsades de pointes.


Figure 1.9: Example of VF with no recognizable P-waves or QRS complexes.


Figure 1.10: Example of first-degree block with P-R interval >0.2 seconds.


Figure 1.11: Mobitz I (second-degree block) with P-R intervals shown in seconds.


Figure 1.12: Mobitz II (second-degree block) with arrows showing P-waves. The P-R interval is stable, and the ratio is 3:1.


Figure 1.13: Third-degree block with P-waves (black arrows) having an SA node rate of 100 bpm and the ventricles depolarizing (blue arrows) at 33 bpm.


Figure 1.14: Example of LBBB with defining features labeled.


Figure 1.15: Changes in R-wave morphology as differences in left and right depolarization produce an M-shaped wave.


Figure 1.16: Typical RSR’ pattern (upper) and slurred S-wave pattern (lower) of RBBB.


Figure 1.17: Schematics of normal WPW syndrome conductivity pathways.


Figure 1.19: Changes in QT interval in moderate hypercalcemia and hypocalcemia.


Figure 1.20: J-waves arise during hypothermia but can also be caused by hypercalcemia.


Figure 1.21: A prominent U-wave and inverted T-wave associated with hypokalemia.


Figure 1.22: Early after-depolarizations occurring in a cardiac action potential due to poor K+ conductance in hypokalemia.


Figure 1.23: Peaked T-waves with mild hyperkalemia.


Figure 1.24: Big T, and little p and r of moderate hyperkalemia.


Figure 1.25: Preterminal ECG of severe hyperkalemia.


Ischemic cardiomyopathy, microscopic.


Left ventricular aneurysm containing mural thrombus, gross.


Left ventricular aneurysm, gross.


Remote myocardial infarction (weeks to years), gross.


Remote myocardial infarction (>2 months), microscopic.


Remote myocardial infarction (3 to 4 weeks), microscopic.


Intermediate (healing) myocardial infarction (1 - 2 weeks), microscopic.


Acute myocardial infarction with rupture and tamponade, gross.


Acute myocardial infarction with rupture, gross.


Acute myocardial infarction, gross.


Acute myocardial infarction (3 - 4 days), extensive neutrophilic infiltrate, microscopic.


Acute myocardial infarction (1 - 2 days), hyperemic border, microscopic.


Acute myocardial infarction (1 - 2 days) with early neutrophilic infiltrate, microscopic.


Early acute myocardial infarction (<1 day) with contraction band necrosis, microscopic.


Early acute myocardial infarction (<12 hours) with loss of cross striations, microscopic.


Normal myocardium, microscopic.


Thrombosis of coronary artery, microscopic.


Thrombosis of coronary artery, gross.


Coronary artery, atheromatous plaque with disrupted fibrin cap, microscopic.


Coronary artery, hemorrhage into plaque, gross.


Coronary atherosclerosis, occlusive, microscopic.


Coronary atherosclerosis, complicated by calcification, microscopic.


Coronary atherosclerosis, intimal plaque, microscopic.


Coronary atherosclerosis, composite, microscopic.


Coronary atherosclerosis, severe, gross.


Coronary atherosclerosis, minimal, gross.


Coronary atherosclerosis, cross sections, gross.


Normal coronary artery, microscopic.


Ancel Keys


Renata Gomes pictured in 2019.


Frits Prinzen


Tetralogy of Fallot


Blood flow through the valves


Main complications of persistent  high blood pressure


Dextro-transposition of the Great Arteries


An example of a drug-eluting stent. This is the TAXUS Express 2  Paclitaxel-Eluting Coronary Stent System, which releases  paclitaxel .


A stethoscope.


Cardiologists use diagrams like this: a heart with an  ECG  indicator


Grade 1 hypertension


Cross-section of the heart, viewed from the front. The aortic valve separates the  left ventricle  from the  aorta .


Heart viewed from above, with atria removed to expose the valves. The aortic valve has three sections called leaflets that open to let blood flow.


1966 DeBakey  ventricular assist device . [ 28 ]


Carmat's artificial heart.


Jarvik-7 Artificial Heart Prototype without Valves


Soft Total Artificial Heart, developed in the functional material laboratory at ETH Zürich


3D Medical Animation still shot of Artificial Heart Valve


Caged ball valve


tilting-disc valve


Bileaflet valve


Type I atrial flutter, counterclockwise rotation with 3:1 and 4:1  AV nodal  block.


Atrial flutter with a two to one block. Note the P waves hiding in the T waves in leads V1 and V2


BRC Introduced the use of zebrafish as an animal model in biomedical research at Qatar University


Biosafety level 3 (BSL3) lab at BRC, Qatar University


Ventral view of the viscera of  Chtenopteryx sicula , showing the presence of the branchial hearts.


Cannon A wave


An  electrocardiogram technician  can have many roles in the hospital, based around the recording of  electrocardiograms , as depicted here


The Norwegian mountain runner  Jon Tvedt  engaging in a strenuous run: it is suggested that the central governor ensures that such  endurance exertion  does not threaten the body's  homeostasis  and physical integrity


Cerebrovascular system


The  ophthalmic artery  and its branches


The anterior and posterior circulations meet at the  circle of Willis , pictured here, which rests at the top of the  brainstem . Inferior view.


Dural venous sinuses  bordered by hard meninges (shown in blue) direct blood outflow from cerebral veins to the  internal jugular vein  at the  base of skull .


Graphical user interface of the eMurmur CAA system [ 7 ]  showing the incoming signal in real time. This CAA system includes live noise detection algorithms that ensure that the recorded signal is of sufficient quality.


The mobile device based result screen of the eMurmur CAA system, [ 7 ]  showing the AHA classification, murmur analysis results (no murmur, innocent or pathologic murmur, additional descriptive data), heart rate, and playback option of the recordings.


The laptop based SensiCardiac CAA software program, [ 9 ]  showing the recorded heart sounds and ECG signal, as well as the analysis results.


Contrast-enhanced  renal ultrasonograph , showing a renal cell carcinoma successfully treated with thermal ablation, as no contrast enhancement is seen [ 1 ]


Unspecific cortical lesion on CT is confirmed cystic and benign with contrast-enhanced renal ultrasonography using image fusion. [ 1 ]


Door leading to a CCU in Kerala.


Coronary arteries  labeled in red text and other landmarks in blue text


Schematic view of the heart


Base and diaphragmatic surface of heart showing some cardiac veins


Cast of coronary arteries (right = yellow, left = red)


Lesion specific calcium score


In some locations, a prehospital 12 lead ECG may be transmitted to the emergency department with the use of a  Bluetooth  capable cardiac monitor and cell phone.


Sonographer doing an echocardiogram of a child


Echocardiogram in the parasternal long-axis view, showing a measurement of the heart's left ventricle


Coronary artery IVUS with lumen inside yellow line and atherosclerotic plaque in green


Timely course of parallel recordings of ECG, impedance waveforms, and their relationships to RBC orientation


The arrow indicates a fusion beat on this ECG.


Hajdu–Cheney syndrome has an  autosomal dominant  pattern of  inheritance . The above example is demonstrated in the case of a carrier parent.


Heart rate variability visualized with R-R interval changes


Electrocardiogram (ECG) recording of a canine heart that illustrates beat-to-beat variability in  R–R interval  (top) and  heart rate  (bottom).


A simplified representation of the neurovisceral integration model [ 11 ]


Front of  thorax , showing surface relations of  bones ,  lungs  (purple),  pleura  (blue), and  heart  (red outline). The locations of best  auscultation  for each  heart valve  are labeled with "M", "T", "A", and "P". First heart sound: caused by atrioventricular valves –  Mitral  (M) and  Tricuspid  (T).  Second heart sound caused by semilunar valves –  Aortic  (A) and  Pulmonary/Pulmonic  (P).


Diagram showing relations of opened heart to front of thoracic wall. Ant. Anterior segment of  tricuspid valve . A O.  Aorta . A.P. Anterior  papillary muscle . In.  Innominate artery . L.C.C. Left  common carotid artery . L.S. Left  subclavian artery . L.V.  Left ventricle . P.A.  Pulmonary artery . R.A.  Right atrium . R.V.  Right ventricle . V.S.  Ventricular septum .


Phonocardiogram  from normal and abnormal heart sounds.


The hexaxial reference system is a diagram that is used to determine the heart's electrical axis in the frontal plane.


Cabrera circle


Diagram showing how the polarity of the QRS complex in leads I, II, and III can be used to estimate the heart's electrical axis in the frontal plane.


Cardiac catheter placement through the groin


An intra-aortic balloon pump


Aortic pressure curve in the presence of an intra-aortic balloon pump


Vital parameters recorded during a 1:2 counter-pulsation


Isochrone map of the  Austro-Hungarian Empire , in 1912. The railway lines are clearly visible.


Isochrone map showing drive times around airports in northern Finland, created using  GIS software  (2011)


Rates of travel in America, 1800 to 1930. [ 7 ]  plate 138, page 366)


Francis Galton's  first known isochronic map published for the  Proceedings of the Royal Geographical Society , 1881. It shows the travel times in 1881 from  London ,  United Kingdom  to different parts of the world in days. It assumes that there are favourable travel conditions and that travel arrangements over land have been made in advance. It assumes travelling methods of the day within a reasonable cost.


An early isochrone map of  Melbourne  rail transport travel times, 1910–1922


Isochrone map of Toronto comparing travel times between bicycle and public transit (2016) [ 1 ]


Electrode placement for Lewis lead; RL electrode (green), not shown, remains on leg


Structure of a  chylomicron  (the largest lipoprotein).   ApoA ,  ApoB ,  ApoC ,  ApoE  are  apolipoproteins ; green particles are  phospholipids ;  T  is  triglyceride ;  C  is  cholesterol ester .


Simplified flowchart showing the essentials of lipoprotein metabolism.


LDL has been associated with the progression of atherosclerosis and blockage of the artery lumen, because it can carry cholesterol into smaller vessels. But LDL is also essential for carrying lipids that keep the human body alive, including in those small vessels.


Features of progenitor cells and stem cells


The physiological effects of stress on the body


A diagram explaining factors affecting  arterial pressure


Structural formula of the potassium-sparing diuretics. Click to enlarge.


Figure 1: Idealized pressure–volume diagram featuring cardiac cycle components.


Figure 2. Calculation of Tau (Glantz method)


Pressure-Volume loops showing end-systolic pressure volume relationship


End-diastolic pressure volume relationship.


Pressure-volume area plot.


Preload recruitable stroke work.


Frank–Starling curve.


Arterial elastance


Dilated Cardiomyopathy


Left Ventricular Hypertrophy


Restrictive cardiomyopathy


Aortic stenosis


Mitral stenosis


Aortic regurgitation


Mitral regurgitation


Assortment of sonomicrometer crystals


Calculation of correction volume in  [1]


Calculation of EDPVR and ESPVR


Selective pulmonary angiogram revealing significant thrombus (labelled A) causing a central obstruction in the left main pulmonary artery


A simplified diagram of one common pulse duplicator design. A piston is used to create and release pressure, simulating blood flow. Note that both valves would not be fully open at the same time in actual operation.


A pulse oximeter probe applied to a person's finger


Absorption spectra of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb) for red and infrared wavelengths


Simplified principle of operation of a transmissive LED pulse oximeter


The inner side of a pulse oximeter


The phenomenon of vessel restenosis, an immune response to damaged tissue, is known to be a common adverse event and the Achilles heel of angioplasty and stenting. Reducing restenosis is one of the highest priorities in research and the development of new endovascular technologies. Restenosis rates of drug-eluting stents appear to be significantly lower than  bare-metal stents , and research is underway to determine if drug-coated balloons also improve restenosis outcomes.


Conceptual schematic illustrating effectiveness of endovascular interventions on lumen diameter to improve blood flow as represented by acute gain, late loss (restenosis), and net gain.


Ventricular fibrillation


SATRO-ECG System


Atheroma blocking an artery lumen [ 8 ]


Schematic representation of normal sinus rhythm showing standard wave, segments, and intervals


Example of a sinus rhythm with  bifascicular block


A sonographer performing pediatric  echocardiography


Wiggers diagram  of various events of a  cardiac cycle , with  2nd  heart sound at bottom.


A wall-mounted Automated External Defibrillator (AED) at a sporting venue


Positioning for stethoscope to best hear Still's Murmur


An early commercial ECG machine, built in 1911 by the Cambridge Scientific Instrument Company


Schema of Einthoven galvanometer, with  quartz  filament marked a-a'- 1903


S-ICD lead and generator position


Ventricular pacemaker with 1:1 retrograde ventriculoatrial (V-A) conduction to the atria (arrows).


Parasympathetic nervous system mediated by vagal innervation


Close-up illustration of typical left ventricular assist device (LVAD)


1966 DeBakey ventricular assist device. [ 22 ]


Figure 1.  The pressure and velocity measured in the ascending aorta in an elderly man.


Figure 2. The wave intensity calculated from the measured pressure and velocity measured in the ascending aorta of an elderly man.


Figure 3. The pressure (minus the diastolic pressure) measured in the ascending aorta of an elderly man separated into the forward and backward pressures using wave intensity analysis.


ZOLL LifeVest WCD showing vest and power supply [ 18 ]


Zoll LifeVest WCD on person [ 18 ]


Overview of all analyses from the VEST study concerning mortality rates


The Windkessel analogy illustrated.


2-Element Windkessel Circuit Analogy Illustrated


4-Element compared to the 2- and 3-Element Windkessel models


Graph Evaluating Systole and Diastole Pressure


Drawing of the ECG, with labels of intervals


Cellular mechanisms of early afterdepolarizations (EADs) and delayed afterdepolarizations (DADs).


Drugs affecting the  cardiac action potential


Effect of class III drugs on length of action potential


Common anti-arrhythmic drugs under the modernized classification according to Lei et al. 2018


A diagram showing the  chain of survival


Defibrillator training kit


An AED at a railway station in  Japan


The universal AED sign, developed by the  International Liaison Committee on Resuscitation  and adopted as  ISO 7010  E010


The use of easily visible status indicator and pad expiration date on a Cardiac Science G3 AED


Usual placement of pads on chest


Bidomain model domain, considering the intracellular and extracellular region as a unique physical region representing the heart, and an extramyocardial region representing the torso or a fluid bath.


BIOTRONIK in the Czech Republic, 2011.


The former  Postfuhramt , acquired in 2012 by BIOTRONIK.


BIOTRONIK ICS 3000 and PK-199


Evolution in time only (i.e. case of a single cardiac cell) of the Bueno-Orovio ionic model variables

 u
 ,
 v
 ,
 w
 ,
 s

 {\displaystyle u,v,w,s}


Image showing the ECG characteristics of a  right bundle branch block  and a  left bundle branch block . In both cases, the late portion of the widened  QRS complex  arises from an anomalously conducted depolarization impulse. The direction of this delayed depolarization vector differs based on the structure that is blocked; the impulse travels  anterior  toward the  right ventricle  in RBBB and  lateral  toward the  left ventricle  in LBBB.


Figure. 1: Cable theory's simplified view of a neuronal fiber


Figure. 2: Fiber capacitance


Basic cardiac action potential


Different shapes of the cardiac action potential in various parts of the heart


Action potentials recorded from sheep atrial and ventricular cardiomyocytes with phases shown. Ion currents approximate to  ventricular action potential .


Figure 2a: Ventricular action potential (left) and sinoatrial node action potential (right) waveforms. The main ionic currents responsible for the phases are below (upwards deflections represent ions flowing out of cell, downwards deflection represents inward current).


The  electrical conduction system of the heart


Drugs  affecting the cardiac action potential. The sharp rise in voltage ("0") corresponds to the influx of sodium ions, whereas the two decays ("1" and "3", respectively) correspond to the sodium-channel inactivation and the repolarizing efflux of potassium ions. The characteristic plateau ("2") results from the opening of voltage-sensitive  calcium channels .


Graphical representation of the electrical conduction system of the heart that maintains the  heart rate  in the  cardiac cycle


Different wave shapes generated by different parts of the  heart's action potential


The ECG complex. P=P wave, PR=PR interval, QRS=QRS complex, QT=QT interval, ST=ST segment, T=T wave


Principle of ECG formation. The red lines represent the depolarization wave, not bloodflow.


A Welch Allyn PIC 50 monitor/defibrillator from an Austrian EMS service.


A closeup view of the screen of the PIC 50.


ZOLL R Series Plus external monitor/defibrillator


3D rendering showing thick myocardium within the heart wall.


Differently oriented cardiac muscle fibers.


Cardiac muscle


Cardiac sarcomere structure


Illustration of a cardiac muscle cell.


Intercalated discs  are part of the cardiac muscle cell  sarcolemma  and they contain  gap junctions  and  desmosomes .


Dog cardiac muscle (400X)


The swirling musculature of the heart ensures effective pumping of blood.


Image showing the cardiac pacemaker or  SA node , the primary pacemaker within the  electrical conduction system of the heart


Schematic representation of the sinoatrial node and the atrioventricular bundle of His. The location of the SA node is shown in blue. The bundle, represented in red, originates near the orifice of the coronary sinus, undergoes slight enlargement to form the AV node. The AV node tapers down into the bundle of His, which passes into the ventricular septum and divides into two bundle branches, the left and right bundles. The ultimate distribution cannot be completely shown in this diagram.


Illustration depicting an  ectopic focus


Cardiac Pacemaker's microlyth pacemaker


Cardiac pacemaker's lithium battery-powered pacemaker, the world's first


The company's lithium-iodine bipolar pulse generator


Chest radiographs  of cardiac resynchronization therapy with defibrillator (CRT-D) in an individual with dilated cardiomyopathy after mitral valve replacement (MVR). The leads are: - Atrial lead at the right appendage  - Right ventricular lead at the apex - Left ventricular lead through the coronary sinus. [ 7 ]


The cardiac action potential has five phases. I to1  is active during phase 1, causing a fast  repolarization  of the action potential


Laddergram illustrating interpolated VPBs and concealed conduction


Ross Cowie in 2018


Self-adhesive electrodes of a defibrillator


Anterior-apex placement of electrodes for defibrillation


A circuit diagram showing the simplest (non-electronically controlled) defibrillator design, depending on the inductor (damping), producing a Lown, Edmark or Gurvich Waveform


Image of a  myocardial  action potential. Effective refractory period in green.


Graphical representation of Einthoven's triangle


Use of  real time monitoring  of the heart in an  intensive care unit  in a German hospital (2015), the monitoring screen above the patient displaying an electrocardiogram and various values of parameters of the heart like heart rate and blood pressure


Normal 12-lead ECG


A 12-lead ECG of a 26-year-old male with an incomplete  right bundle branch block  (RBBB)


A patient undergoing an ECG


An ECG electrode


Proper placement of the limb electrodes. The limb electrodes can be far down on the limbs or close to the hips/shoulders as long as they are placed symmetrically. [ 30 ]


Placement of American-color-coded ECG electrodes (using a 5-electrode yoke)


Placement of European-color-coded ECG electrodes (using a 10-electrode yoke)


Placement of the precordial electrodes


The limb leads and augmented limb leads (Wilson's central terminal is used as the negative pole for the latter in this representation)


Diagram showing the contiguous leads in the same color in the standard 12-lead layout


QRS is upright in a lead when its axis is aligned with that lead's  vector


Schematic representation of a normal ECG


Measuring time and voltage with ECG graph paper


Diagram showing how the polarity of the QRS complex in leads I, II, and III can be used to estimate the heart's electrical axis in the frontal plane.


Animation of a normal ECG wave


Formation of limb waveforms during a pulse


An early commercial ECG device (1911)


ECG from 1957


An acute STEMI involving the inferior and right ventricular wall. Reciprocal changes are seen in the anterior leads.


Localisation of the occlusion in the ECG showing STEMI changes


Doctors conduct an electrophysiology study in the hospital's  cardiac catheterization  laboratory


Flatlined  ECG  lead


CPR being performed on a medical-training  mannequin


Simulation of a realistic heart beat.


Schematic diagram of normal sinus rhythm for a human heart as seen on ECG.


Stylized representation of a human torso that describes the domain and the notation considered for the forward problem of electrocardiography. Two separated areas and their boundary are considered, which represent the heart and human torso around it.


Precordial leads in ECG


Three-dimensional torso model including the most organs. [ 12 ]


Ivabradine


Illustration of Implantable Cardioverter Defibrillator (ICD)


A single chamber ICD with its right ventricular lead connected into the header; note, starting from the end of the lead, the tip and adjacent first ring, used to sense the cardiac electrical activity and stimulate the right ventricle, the coil and the two rings for atrial sensing.


A normal chest X-ray after placement of an ICD, showing the ICD generator in the upper left chest and the ICD lead in the right ventricle of the heart. Note the 2 opaque coils along the ICD lead.


S-ICD lead and generator position


Sketch of an already-implanted cardioverter-defibrillator


Lead II  electrocardiogram  (known as "rhythm strip") showing  torsades de pointes  being shocked by an implantable cardioverter-defibrillator back to the patient's baseline  cardiac rhythm .


Remote control for a  Biotronik  implantable loop recorder used by the patient


Libin Cardiovascular Institute logo


A Lifepak 15 Monitor/Defibrillator


Normal P wave, shown in darker red


Diagram demonstrating features of a normal  sinus rhythm  electrocardiogram wave


Characteristic peaked P wave of cor pulmonale


P-wave changes in left and right atrial hypertrophy


An  ECG  in a person with a single-chamber pacemaker to the  atrium . Note the circle around one of the sharp electrical spikes in the position where the P wave would be expected.


An ECG of a person with a dual-chamber pacemaker


ECG rhythm strip of a threshold determination in a patient with a temporary (epicardial) ventricular pacemaker. The epicardial pacemaker leads were placed after the patient collapsed during  aortic valve  surgery. In the first half of the tracing, pacemaker stimuli at 60 beats per minute result in a wide QRS complex with a  right bundle branch block  pattern. Progressively weaker pacing stimuli are administered, which results in  asystole  in the second half of the tracing. At the end of the tracing, distortion results from muscle contractions due to a (short) hypoxic  seizure . Because decreased pacemaker stimuli do not result in a ventricular  escape rhythm , the patient can be said to be pacemaker-dependent and needs a definitive pacemaker.


Right atrial and right ventricular leads as visualized under x-ray during a pacemaker implant procedure. The atrial lead is the curved one making a U shape in the upper left part of the figure.


Single-chamber VVIR/AAIR pacemaker


Dual-chamber DDDR pacemaker


Three leads can be seen in this example of a cardiac resynchronization device: a right atrial lead (solid black arrow), a right ventricular lead (dashed black arrow), and a coronary sinus lead (red arrow). The coronary sinus lead wraps around the outside of the left ventricle, enabling pacing of the left ventricle. Note that the right ventricular lead in this case has two thickened aspects that represent conduction coils and that the generator is larger than typical pacemaker generators, demonstrating that this device is both a pacemaker and a cardioverter-defibrillator, capable of delivering electrical shocks for dangerously fast abnormal ventricular rhythms.


Posteroanterior and lateral  chest radiographs  of a pacemaker with normally located leads in the right atrium (white arrow) and right ventricle (black arrowhead), respectively


Two types of remote monitoring devices used by pacemaker patients


In 1958,  Arne Larsson  (1915–2001) became the first person to receive an implantable pacemaker. He had 26 devices during his life and campaigned for other patients needing pacemakers.


Illustration of implanted cardiac pacemaker showing locations of cardiac pacemaker leads


The first lithium-iodide cell-powered pacemaker. Invented by Anthony Adducci and Art Schwalm.  Cardiac Pacemakers Inc . 1972 [ 87 ]


Pacemaker rates


ECG beat


Block diagram of the pre-processing phase of the Pan–Tompkins algorithm.


Example of Pan–Tompkins processing. [ 5 ]


Schematic representation of a normal  sinus rhythm  EKG wave


PQ segment divided into parts corresponding to the location in heart's  electrical conduction system


Purkinje fiber just beneath the endocardium


Schematic representation of a normal  sinus rhythm  ECG wave.


Diagram showing how the polarity of the QRS complex in leads I, II, and III can be used to estimate the heart's electrical axis in the frontal plane.


Schematic representation of the QRS complex.


Various QRS complexes with nomenclature.


Illustrations of the tangent and threshold methods of measuring the QT interval


Upper limit of normal QT interval, corrected for heart rate according to  Bazett's formula , [ 5 ]  Fridericia's formula, [ 10 ]  and subtracting 0.02 s from QT for every 10 bpm increase in heart rate. [ 13 ]  Up to 0.42 s (≤ 420 ms) is chosen as normal QTc of QT B  and QT F  in this diagram. [ 14 ]


Distribution of QT intervals amongst healthy males and females, and amongst those with congenital long QT syndrome


Beat-to-beat measurement of QT interval using two-dimensional signal warping (2DSW).


Example traces of heart rate and QT interval variability in a normal heart and after myocardial infarction.


Schematic of an  electrophysiological  recording of an action potential showing the various phases that occur as the wave passes a point on a cell  membrane .


Effective Refractory Period


ECG demonstrating sinoventricular conduction due to hyperkalemia


Schematic representation of normal  ECG


Illustration of ST segment elevation and depression


Normal T wave


True electrical and mechanical capture


False capture with visible phantom beats [ 3 ]


A 'U' wave as seen on  Electrocardiogram (ECG)


An electrocardiogram of an 18-year-old male showing 'U' waves, most evident in lead V3.


The action potential of a ventricular myocyte


Pandey at award ceremony in 2023


A health promotion coordinator at Fleet Activities Sasebo, from Augusta, Ga., checks a sailor's blood pressure.


Representatives from the American Heart Association meeting with US Representative  Martha Roby


American Heart Association, Fellowship of the American Heart Association's Stroke Council


BHF-funded clinical research


British Heart Foundation shop, Loue, Cornwall


British Heart Foundation store, Hammersmith, London


The Canadian Cardiovascular Society logo.


CRY logo


Corindus Vascular Robotics.


The 57 institutional members of the ECS.


ESC Congress 2019, Paris


Former logo, used until 2016


Heart and Stroke Foundation's fundraising "Big Bike"


InCor


Executive DirectorCPEIC, Multan.


Academic Session in Progress at MIC


Gate


Logo of the Resuscitation Council UK


Surgeons Of Hope logo


Pediatric Heart Center of Nicaragua in construction


ESPVR and EDPVR are dynamic properties of the myocardium.


The pressure-volume area (PVA) is the total mechanical energy generated by ventricular contraction.


As the level of support increases, aortic pressure is maintained independent of ventricular function. Perfusion pressure is uncoupled from heart function (1-4). [ 2 ]


A person undergoing a procedure where an 8 F introducer was placed in the right  jugular vein  using a 5F MAK access kit. A 7 F  balloon tipped catheter  was introduced via the venous sheath, the balloon was inflated and the catheter was advanced through the  right heart chambers  into the  pulmonary capillary wedge position . Right sided pressures were obtained and  cardiac output  was measured using thermodilution.


Right heart cath using a Swan-Ganz pulmonary artery catheter


Posteroanterior and lateral  chest radiographs  of a pacemaker with normally located leads in the right atrium (white arrow) and right ventricle (black arrowhead), respectively.


Atrial septal defect with left-to-right shunt


Schematic representation of normal  sinus rhythm  as seen on an ECG. The QRS complex is shown in the center.


Metal detectors used for security screening


'Burn' mark remaining one day after DC electrical cardioversion


LIFEPAK 20e Defibrillator and Monitor displaying synchronization with QRS complexes. (arrowheads)


A coronary angiogram (an X-ray with  radiocontrast agent  in the  coronary arteries ) that shows the left  coronary circulation . The distal  left main coronary artery  (LMCA) is in the left upper quadrant of the image. Its main branches (also visible) are the  left circumflex artery  (LCX), which courses top-to-bottom initially and then toward the centre/bottom, and the  left anterior descending  (LAD) artery, which courses from left-to-right on the image and then down the middle of the image to project underneath the distal LCX. The LAD, as is usual, has two large diagonal branches, which arise at the centre-top of the image and course toward the centre/right of the image.


Coronary Angiography (CAG [ 3 ] ).


Coronary angiography of a critical sub-occlusion of the common trunk of the left coronary artery and the circumflex artery. (See arrows)


Angiography (left) and CT (middle and right) of chronic total occlusion lesions at the left anterior descending coronary artery (LAD) and right coronary artery (RCA).


iFR calculation uses a ratio of proximal and distal coronary pressures over the wave-free period in diastole


The flow velocity, pressure, and instantaneous microvascular resistance were calculated over the wave-free period and during that of the complete cardiac cycle. Flow velocity is higher, and pressure is lower over the wave-free period. This results in lower microvascular resistance during the wave-free period in comparison to the complete cardiac cycle. Values are expressed as median+/-interquartile range. Used with permission: Sen S, Asrress KN, Nijjer S, et al. J Am Coll Cardiol 2013;61:1409–20.


12-lead  electrocardiogram  showing ST-segment elevation (orange) in I, aVL and V1-V5 with reciprocal changes (blue) in the inferior leads, indicative of an anterior wall myocardial infarction.


Angiogram  of the coronary arteries.


Micrograph  of a  myocardial infarction  (ca. 400x H&E stain ) with prominent contraction band  necrosis .


Information card published by the  National Heart, Lung, and Blood Institute  urging people with symptoms of angina to call the emergency medical services.


Typical  electrocardiogram  of an  ST segment  elevation myocardial infarction. ST elevation in  leads  I, aVL and V1-V5 indicates an anterior wall myocardial infarction and is shown in orange; reciprocal ST depression in leads II, III and aVF is shown in blue.


Coronary angiography and angioplasty in acute myocardial infarction (left: RCA closed, right: RCA successfully dilated)


Tight, critical stenosis (95%) of the proximal LAD in a patient with  Wellens' warning


Stent placement.  A , the catheter/DES device is inserted across the lesion.  B , the balloon is inflated using saline fed through the catheter portion into the DES/Balloon component, expanding the DES and compressing it against the artery wall.  C , the catheter and deflated balloon removed leaving the DES firmly embedded in the artery wall.


A  coronary stent  placed by percutaneous coronary intervention.


Figure 3: For maximal reliability, the PLR test must be performed following some rules. One possible variation of PLR starts from the semi-recumbent position 1. The second step comprises going down the trunk and raise legs maintaining the angle between them using the automatic motion of the bed for avoiding artifacts. Finally, the third step goes back to position 1 to ensure that the subject recovers the previous hemodynamic parameters.


Figure 4: The link between the fiber length and myocardial contractile force is illustrated. Within the preload dependent zone, the SV raises while the ventricular preload does too, however, in the preload independent zone a higher preload or further fluid boluses will not improve the SV.


Figure 5: HRV parameters recorded during the recovering of a patient with sepsis are depicted. It is noticeable the growing trend according to the improving. Hence, this data could be used to drive a prognosis.


Figure 6: The Fast Fourier Transformation (FFT) and spectral methods let quantify components of the HRV, by classifying the frequencies in three regions: High (HF= 0.15-0.4 Hz), Low (LF= 0.04-0.15 Hz) and Very-Low (VLF= 0.003-0.04 Hz) frequency powers. The most valuable zone is the HF because is modulated exclusively by the SNP. The LF is regulated by both, the PNS and SNS (Sympathetic Nervous System). And the VLF modulation is unclear, but it is thought that could be influenced by the PNS and renin-angiotensin-aldosterone system. [ 28 ]


Coronary artery bypass surgery during mobilization (freeing) of the  right coronary artery  from its surrounding tissue,  adipose tissue  (yellow).  The tube visible at the bottom is the aortic cannula (returns blood from the  HLM ).  The tube above it (obscured by the  surgeon  on the right) is the venous cannula (receives blood from the body).  The patient's  heart  is stopped and the  aorta  is cross-clamped.  The patient's head (not seen) is at the bottom.


Wasserman 9 Panel-Plot for 36-year-old man.


A man with  congestive heart failure  and marked jugular venous distension.  External jugular vein marked by an arrow.


Pitting edema during and after the application of pressure to the skin.


Example ultrasound of an athlete


Aerobic / Endurance  and  Resistance/Strength exercise  impact on  cardiac remodeling  and growth [ 7 ]


The human heart


Deposits of plaque, narrowing the coronary artery blocking the blood flow.


Otherwise called  balloon angioplasty . Procedure to widen the narrowed artery that supplies blood to the heart.


Hippolyte Bernheim (1840-1919)


Artery wall structure, showing intimal layer [ 9 ]


Cardiac Amyloidosis, H&E stain.  Dark pink material showing cardiac myocytes, and light pink material interspersed throughout is amyloid.


Hemopericardium , wherein the  pericardium  becomes filled with  blood , is one cause of cardiac tamponade.


General scheme to identify possible courses of normal and ectopic coronary origin. AL = antero-left; AR = antero-right; Cx = circumfles artery; IM = intramural; IS = intraseptal; LAD = left anterior descending artery; M = mitral valve; P = posterior; PP = prepulmonic; RA = retroaortic; RC = retrocardiac; RCA = right coronary artery; T = tricuspid valve.


Cross-sectional computed tomography angiogram of RCA (between aorta and pulmonary artery) at the worst intramural site of compression (right anterior oblique projection). Black arrow = compressed intramural RCA.


Intravascular ultrasound imaging of intramural RCA during systole (left) and diastole (right) in a patient with mild symptoms.


Clogged artery


Transcripts associated with CAD identified by  RNA-seq . The differentially expressed genes identified by RNAseq were curated by automated and manual analysis to identify the molecular pathways involved. The resulting pattern points to changes in the 'immune synapse', which involves both endocytic pathways of T cell receptor-containing vesicles, as well as ciliary protrusions that couple to intracellular signaling pathways.


Micrograph  of a  coronary artery  with the most common form of coronary artery disease ( atherosclerosis ) and marked  luminal  narrowing.  Masson's trichrome .


Illustration depicting coronary artery disease


Coronary angiogram of a male


Coronary angiogram of a female


Deaths due to ischaemic heart disease per million persons in 2012     160–288    289–379    380–460    461–576    577–691    692–894    895–1,068    1,069–1,443    1,444–2,368    2,369–7,233


Disability-adjusted life year  for ischaemic heart disease per 100,000 inhabitants in 2004. [ 132 ]      no data      <350      350–700      700–1,050      1,050–1,400      1,400–1,750      1,750–2,100      2,100–2,450      2,450–2,800      2,800–3,150      3,150–3,500      3,500–4,000      >4,000


A proposed disease hypothesis for SCAD


This is a representative video of coronary angiography. While it does not display SCAD, it highlights the technique used to identify the condition.


This is a representative image of two types of intracoronary imaging, OCT (left) and IVUS (right).


Image depicting atherosclerosis.


Coronary Angiography showing occluded coronary arteries.


Image of a computed tomography scanner.


Coronary angiography of a patient with a heart attack.


Nail clubbing  of fingers in a patient with Eisenmenger syndrome. First described by  Hippocrates , clubbing is also known as "Hippocratic fingers".


Signs and symptoms of severe heart failure


Severe peripheral pitting edema


Kerley B lines  in  radiograph  of acute cardiac decompensation. The short, horizontal lines can be found everywhere in the  right lung .


Model of a normal heart (left); and a weakened heart, with over-stretched muscle and dilation of  left ventricle  (right); both during  diastole


Chest radiograph  of a lung with distinct  Kerley B lines , as well as an  enlarged heart  (as shown by an increased  cardiothoracic ratio , cephalization of pulmonary veins, and minor  pleural effusion  as seen for example in the right  horizontal fissure . Yet, no obvious lung edema is seen. Overall, this indicates intermediate severity (stage II) heart failure.


Siderophages (one indicated by white arrow) and pulmonary congestion, indicating left  congestive heart failure


Wiggers diagram , depicting the cardiac cycle. Two complete cycles are illustrated.


End Diastolic Pressure Volume Relationship


Histopathology of giant-cell myocarditis, with multinucleated giant cells. H&E stain.


Inferior left ventricle wall scar, short axis echocardiography view


Diffuse ST elevation in a young male due to myocarditis and pericarditis


Lymphocytic myocarditis (white arrow points to a lymphocyte), commonly showing myocyte necrosis (black arrow), seen as hypereosinophilic cytoplasm with loss of striations.


Endomyocardial biopsy  specimen with extensive  eosinophilic  infiltrate involving the  endocardium  and  myocardium  ( hematoxylin and eosin  stain)


Giant-cell myocarditis , with multinucleated giant cells.


Micrograph  of an excised  aortic valve   papillary fibroelastoma  showing that the avascular branching papillae are covered by endothelium.  H&E stain .


ECG showing right axis deviation


Hexaxial reference system


Relative position of the heart and stomach in the human body


Human stomach with  fundus  part visible and Vagus nerve


Gastric nerve connections to the  spinal cord  and  brain   medulla oblongata , which regulate the movements of the stomach


Streptococci


Aminoglycoside


Defibrillator training kit


Arrhythmogenic right ventricular dysplasia, showing fatty infiltration of right and left ventricle, and poor contraction of right ventricle


Myxomatous degeneration of the aortic valve, common in Marfan syndrome


Echocardiogram showing left ventricle


The Japanese octopus traps after which this disease is named [ 13 ]


An example EKG for pulseless electrical activity. In this rhythm, cardiac activity will be seen on electrocardiogram, but a pulse will not be felt on provider's exam.


An EKG showing asystole, or "flat-lining."


Echocardiogram is a study in which an ultrasound is used to exam the function of the heart. In Traumatic cardiac arrest, an echocardiogram may show ineffective motion of the heart and may provide clues that point to a specific cause of the arrest.


Left ventricular aneurysm


An ECG of a person with a left ventricular aneurysm. Note the ST elevation in the anterior leads.


Caffeine 's principal mode of action is as an  antagonist  of adenosine receptors in the brain. [ 11 ]


This diagram illustrates how  TAAR1  activation induces  incretin -like effects through the release of gastrointestinal hormones and influences food intake,  blood glucose  levels, and  insulin  release. [ 76 ]  TAAR1 expression in the periphery is indicated with "x". [ 76 ]


A picture showing the sites of action of diuretics in the renal tubule.


Angioedema, one of the rare side effects of ACEI and ARB.


Formation of plaque (fatty deposit) in arterial wall.


Clinical presentations of rhabdomyolysis.


Thrombosis, occurs when blood clots form within blood vessels and limit the flow of blood.


Jaundice, a common side effect caused by vitamin K antagonists.


Activated charcoal tablet.


Man chewing khat


Mechanism of the Non-Beta Oxidation pathway for the biosynthesis of S-Cathinone in the Khat plant


Chemical structure of bupropion, a cathinone derivative


Ephedrine Sulphate (1932), Ephedrine Compound (1932), and Swan-Myers Ephedrine Inhalant No. 66 ( circa  1940).


The four stereoisomers of ephedrine.


Ephedrine tablets.


Proposed biosynthetic pathway of ephedrine from  L -phenylalanine and pyruvic acid. [ 88 ] [ 89 ]


A Baqsimi nasal glucagon canister


Metabolic regulation of glycogen by glucagon.


Meldonium and its various forms of packaging showing 250 mg capsules and the injection 10% 5 ml


Carnitine synthesis


The carnitine shuttle system. ( Red : acyl-CoA,  Green : carnitine,  Red+green : acylcarnitine,  CoASH : coenzyme A,  CPTI : carnitine palmitoyltransferase I,  CPTII : carnitine palmitoyltransferase II,  1 : acyl-CoA sintetase,  2 : translocase,  A : outer mitochondrial membrane,  B : Intermembrane space,  C : inner mitochondrial membrane,  D : mitochondrial matrix)


Structure of meldonium


Synthesis of mephentermine


One possible synthesis, starting from 3-methylbenzaldehyde


3-MMC as prepared for recreational use.


Space-filling model of phenylpropanolamine.


Two pairs of  enantiomers :  ephedrine  (top) and pseudoephedrine (bottom).


A warning at an Australian pharmacy


ACT-333679, the  active metabolite


Synthesis of Selexipag


Crystal structure of  Vammin , a  VEGF-F  from a snake venom


Schematic representation of the different isoforms of human VEGF


Types of VEGF and their  VEGF receptors . [ 20 ] [ self-published source? ]