…located anywhere in the atria. In most cases, the premature atrial impulse is conducted to the ventricles, which results in ventricular depolarization and the appearance…

…entry circuit involves the atria, atrioventricular node, accessory pathway and the ventricles. In most cases, the re entry is induced by a premature atrial beat…

…These situations are as follows: Premature ventricular depolarization: As exemplified in Figure 1, if the atrial impulse reaches the ventricular His Purkinje system too early…

…entry is induced by a premature atrial beat reaching the atrioventricular node while some fibers are still refractory. If an atrial impulse reaches the atrioventricular…

…because the ectopic impulse originates in the ventricles and does not influence the atria (with exceptions discussed below). Although premature ventricular contractions are mostly harmless…

…excitation (the ventricles are excited prematurely; refer to Figure 4, third panel). As illustrated in Figure 4 the initial depolarization of the ventricles is slow…

CPR ECG 1 . The initial rhythm is atrial fibrillation. The fifth beat is a ventricular premature beat. A ventricular tachycardia (VT) emerges. As evident, ventricular…

…disability and premature mortality. Cardiovascular conditions associated with obesity include hypertension, dyslipidaemia, coronary artery disease (CAD), atherosclerosis, heart failure (HF), atrial fibrillation and cardiovascular events…

…diminished impulse conduction . Explanation follows: Increased automaticity occurs both in the atria and the ventricles. This initially manifests with premature beats (premature atrial beats or

…bradycardia The following conditions may cause intermittent bradycardia: Extrasystoles (premature ventricular beats or premature atrial supraventricular beats) can cause transient AV blocks by affecting the…

…Tachycardia (JET) VENTRICULAR ARRHYTHMIAS Ventricular tachycardia Fascicular tachycardia FREQUENT ECTOPY Premature ventricular contractions (PVC) Premature atrial contractions (PAC) PACEMAKER RELATED Pacing with rapid ventricular response…

…hyperplasia. A family history is therefore important, particularly in patients with early onset hypertension or premature cerebrovascular disease. PA is associated with cardiac hypertrophy, myocardial…

…threatening arrhythmias. Antiarrhythmic drugs Disopyramide Indications Prophylaxis and treatment of symptomatic ventricular tachyarrhythmias. Prophylaxis and treatment of atrial fibrillation. Effects of disopyramide on ECG, heart…

…node is unlikely to lead to premature death. Moreover, it is still debated whether the transient periods of atrial standstill in sinus bradycardia are associated…

…Agent Standard dose in atrial fibrillation Criteria for dose reduction according to FASS : : : Apixaban 5 mg × 2 2.5 mg × 2 if at least two…

Arrhythmias and arrhythmology Critical care Definition and pathophysiology Atrial fibrillation (AF) is the most frequent supraventricular arrhythmia in patients with acute coronary syndromes (ACS) and…

…and travels in a counterclockwise direction. The activation wavefront propagates in a craniocaudal direction down the right atrial free wall, traverses the cavotricuspid isthmus (CTI…

…left in left ventricular hypertrophy). ST T segment Significant hypertrophy may result in abnormal depolarization of the ventricular myocardium. This is presumably due to a…

…prevalence figures are scarce). Indeed, the strongest risk factor for developing atrial fibrillation is age. Other significant risk factors are as follows: male sex, hypertension…

…on the ECG. The flutter waves (on the contrary to f waves in atrial fibrillation) have identical morphology (in each ECG lead). Flutter waves are…

…evolved significantly; it is no longer viewed merely as an electrical anomaly but as a progressive, complex atrial myopathy. For the practicing cardiologist, mastering the…

…may precede the full tachycardia. It is characterized by short, rapid bursts of atrial activity. In the majority of cases, the arrhythmia is self limiting…

…humps. This is often (but not always) seen on ordinary ECG tracings and it is explained by the fact that the atria are depolarized sequentially…

Arrhythmias and arrhythmology Pharmacology & dosing Definition and pathophysiology Atrial fibrillation (AF) is a major independent risk factor for thromboembolism, including ischaemic stroke. This risk applies…

…of bleeding Low risk 0 3 0.8% Intermediate risk 4 2.6% High risk 5 or more 5.8% Interpretation of ATRIA risk score…

…m2 22 ± 6 29–33 34–39 40 22 ± 6 29–33 34–39 40 ​BSA, Body surface area; LA, left atrial; RA, right atrial.

…wide complex tachycardias actually originate from the atria but the QRS complexes become wide due to abnormal ventricular depolarization (e.g sinus tachycardia with simultaneous…

CPR ECG 1 . The underlying rhythm is atrial fibrillation, which is interrupted by polymorphic ventricular tachycardia (VT). ECG 2 . Polymorphic ventricular tachycardia. ECG 3 . Spontaneous…

…atrial fibrillation. Three QRS T complexes are seen, with the latter two having similar QRS morphology. These beats may originate from the ventricles or atria…

…atrium. An electrode placed in the oesophagus at the right level therefore records atrial depolarisation with an amplitude the surface ECG can never achieve, and…

…HEMORR₂HAGES bleeding risk score is a clinical tool developed to assess the risk of major bleeding in patients with atrial fibrillation (AF) on anticoagulation therapy…

…conversion to sinus rhythm occurs) unless contraindications occur. If hemodynamically stable atrial flutter occurs after the first dose, the second dose can still be given…

Echocardiography Cardiac thromboembolism Thromboembolism is a leading cause of death worldwide (1). Emboli originating in the atria, left atrial appendage (LAA), ventricles, valves, and proximal…

Echocardiography Left ventricular function and its echocardiographic assessment Cardiac function depends on a large number of parameters, including atrial function, valvular function, and ventricular function…

Arrhythmias and arrhythmology ECG Pacemaker mediated tachycardia (PMT) Pacemaker mediated tachycardia may arise if the pacemaker records a rapid atrial rate (e.g. during a…

…Doses in atrial fibrillation Drug Standard dose Reduced dose and criterion : : : Apixaban 5 mg twice daily 2.5 mg twice daily if at least two…

…Qs). This measurement is pivotal in diagnosing and managing congenital or acquired cardiac shunts, such as atrial septal defects (ASD), ventricular septal defects (VSD), and…

…As of 2025, it is recommended to use the CHA₂DS₂ VA score for stroke risk assessment in atrial fibrillation patients. By excluding the sex parameter…

…widely recognized and validated tool used to assess the one year risk of major bleeding in patients with atrial fibrillation (AF) who are taking anticoagulants…

…or < 20% of atrial size 4 10 cm² or 20 40% of atrial size 10 cm² or 40% of atrial size Jet orientation central…

…to acetylcholine. The resulting increase in K+ conductance shortens the atrial action potential duration (APD), hyperpolarizes the membrane potential, and decreases atrial contractility. Analogous electrophysiological…

…a mass. Tamponade occurs when intrapericardial pressure equals or exceeds right atrial pressure. The haemodynamic consequences are progressive impairment of right and left sided filling…

…systolic dysfunction. Levels may also rise with: Left ventricular diastolic dysfunction Valvular heart disease Pulmonary hypertension Ischaemic heart disease Atrial arrhythmias Pericardial disease, including constriction…

…myocardial infarction, stroke, heart failure (HF), atrial fibrillation (AF), aortic disease, and peripheral artery disease (PAD). Diabetes also substantially increases the risk of chronic kidney…

…for evaluating left ventricular diastolic function have evolved considerably in the past two decades. Currently recommended methods evaluate left atrial and left ventricular function, geometry…

…interpretation difficult, including left bundle branch block (LBBB) or pacemaker rhythms. Atrial fibrillation or atrial flutter Patients on medications such as nitrates, beta blockers, or…

…to AV Blocks). Second degree AV block is defined by the intermittent failure of atrial impulses to conduct to the ventricles, resulting in some P…

…sinoatrial block implies that the time interval from the discharge of the impulse in the sinoatrial node to the onset of atrial depolarization is prolonged…

…upper panel). The atrial rate is typically faster than the ventricular rate. It may be very difficult to establish a diagnosis of third degree AV…

…are no absolute contraindications. Refrain or adapt in atrial fibrillation with a rapid and irregular ventricular rate (oscillometric measurement becomes unreliable), lymphoedema or a dialysis…

…posterior wall) ≤ 0.9 cm ≤ 1.0 cm Left atrial volume index ≤ 34 mL/m² ≤ 34 mL/m² TAPSE 17 mm 17 mm E/e…

…that any arrhythmia arising in the atria may have wide QRS complexes if the ventricles cannot be depolarised normally (example: sinus tachycardia together with left…

…2.5 mm tall Right atrial enlargement P wave in V1 Terminal negative component 1 mm × 40 ms Left atrial enlargement Low voltage QRS <…

…when the shock is delivered, and that the thromboembolic risk has been dealt with before the atria begin to contract again. An unsynchronised shock that…

…event, where DOACs have proved inferior. Atrial fibrillation with marked renal failure or on dialysis, where DOACs lack documentation or have only weak evidence. Venous…

…total cholesterol and triglycerides) Atrial fibrillation BMI categories The World Health Organization defines BMI categories as follows: Underweight : Less than 18.5 Normal weight : 18…

…Adverse effects Headache. Nausea. Fever. Atrial fibrillation. Worsening of heart failure. Caution • Used cautiously in patients with acute heart failure. • Clevidipine can cause reflex tachycardia…

…risk. Left Atrial Diameter (LA) : Enlargement of the left atrium is a marker of elevated left ventricular filling pressures and is linked to adverse outcomes…

…myocardial infarction may coexist with adverse effects on stroke, heart failure, cardiovascular mortality and atrial fibrillation. Consequently, alcohol should not be initiated as a cardiovascular…

…Atrial arrhythmias, particularly atrial fibrillation and flutter, are common and may precipitate heart failure [8, 10]. Refractory atrial arrhythmias resistant to antiarrhythmic drugs or repeated…