…R bis wave" (R''). Any negative wave occurring after a positive wave is an S wave. Large waves are referred to by their capital letters…

ECG Video lecture: The QRS complex: Q wave, R wave & S wave

…ventricles, provided that the myocardium and conduction system have repolarized. This appears as a P wave and QRS complex occurring earlier than expected ( Figure 1 )…

…the ventricles it will spread partly or entirely outside of the conduction system and thus produce a wide QRS complex (QRS duration ≥0.12 s)…

…follows: NCT – Narrow complex tachycardias (QRS duration <0,12 seconds) indicate the ventricles are depolarized via the His Purkinje system and thus the impulse originates…

…of any deflection/wave is measured by using the PR segment as the baseline. Refer to Figure 1 . The QRS complex The QRS complex represents…

ECG Troponin is a protein complex expressed in cardiac and skeletal muscle. The complex consists of troponin I (TnI) , troponin C (TnC) and troponin T…

Cardiology Introduction Ventricular tachycardia (VT) represents a complex and potentially lethal spectrum of cardiac arrhythmias that remains a formidable challenge in contemporary cardiovascular medicine. As…

…A Tool for Revascularization Strategy in Complex Coronary Artery Disease The SYNTAX Score is a semi quantitative scoring system designed to assess the complexity of…

Cardiology Definition and terminology Heart failure (HF) is a complex clinical syndrome characterized by symptoms and signs resulting from structural or functional impairment of ventricular…

…highly complex lipid driven inflammatory disease of the arterial intima that serves as the fundamental pathophysiological substrate for acute coronary syndromes (ACS), including ST Elevation…

Arrhythmias and arrhythmology Pharmacology & dosing Pharmacokinetic Considerations Relevant to Dosing Amiodarone exhibits highly variable and complex pharmacokinetics that profoundly influence its dosing strategies. The drug…

…Definition and pathophysiology Obesity is a chronic, relapsing and biologically complex disease characterized by excessive accumulation of adipose tissue. It is an important cause of…

…Definition and terminology Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome characterized by the cardinal symptoms and signs of heart failure …

…from supraventricular tachycardia (SVT) with wide QRS complex. Brugada's algorithm If there is no RS complex in any chest lead (V1–V6) a diagnosis…

Cardiology Clinical medicine Introduction Cardiovascular disease becomes increasingly prevalent with advancing age, while its clinical expression and management become progressively more complex. Older adults, often…

…ST segment elevation implies that the ST segment is elevated above the level of the PR segment. The magnitude of any ST segment deviation is…

…ECG can never achieve, and makes it visible even when it lies buried in the QRS complex or the T wave. The whole value of…

…mean nothing. Capture is verified only when every pacing spike is followed by a wide QRS complex and a pulse that can be felt. The…

…atrial rate (beats/min)? P waves should precede every QRS complex and the P wave should be positive in lead II. Common findings Sinus rhythm …

…recovery patterns within the left ventricle, resulting in a widened QRS complex and secondary ST T wave abnormalities [7]. Diagnostic Criteria The diagnostic requirements for…

…for depolarization and repolarization. It is measured from the beginning of the QRS complex to the end of the T wave. Prolonged QT duration predisposes…

…during ventricular tachycardia can precipitate ventricular fibrillation, whereas a synchronized shock (timed to the QRS complex) avoids this risk. Synchronized cardioversion is used for organized…

…Generally, adenosine is considered safe for patients with narrow complex tachycardia (NCT). Adenosine typically causes a short lasting second or third degree AV block which…

…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…

…valvular function, and ventricular function. A large body of science has demonstrated that these parameters are highly interdependent and rather complex. Indeed, myocardial mechanics constitute…

…to prolonged QT interval The QT interval is the time interval from the beginning of the QRS complex to the end of the T wave…

…ventricular rate slower than 50 beats per minute. P waves with constant morphology preceding every QRS complex. P wave is positive in limb lead II…

…below. PR interval and PR segment The PR interval stretches from the onset of the P wave to the onset of the QRS complex. It…

…QRS complex fails to appear) with a constant PR interval. Third degree AV block: all atrial impulses are blocked in the AV conduction system and…

…Heart rate Heart rhythm The P wave The PR interval The QRS complex The ST segment The T wave The U wave The QT interval…

…trial. Limitations Requires detailed clinical and angiographic data. Calculation can be complex without dedicated software. May not account for all patient specific factors (e.g.…

…angiographically satisfactory stenting may leave clinically relevant residual ischaemia, particularly after complex coronary intervention. The clinical importance of residual disease is also influenced by anatomic…

…stenoses. Higher scores indicate more diffuse or technically complex disease and are associated with a greater relative advantage for CABG over PCI in multivessel disease…

…first year after stenting, although the risk is higher after treatment of ST segment elevation myocardial infarction (STEMI) and following complex PCI. Stent thrombosis remains…

…to the left and downwards). Figure 38 shows the coordinate system where the green area displays the range of the normal heart axis. Figure 1…

…axis (to the left and downwards). Figure 38 shows the coordinate system where the green area displays the range of normal heart axis. Figure 38…

…with the QRS complex (which is negative in lead V1). Isolated T wave inversions also occur in leads V2, III or aVL. In any instance…

…abnormalities, HF and sudden cardiac death. The relationship between glycaemia and cardiovascular disease is complex. Glycaemic control is important for prevention of microvascular complications, but…

…coordinate these two tasks, the heart has an electrical conduction system composed of specialized myocardial cells (henceforth referred to as conduction cells). These cells form…

…of congenital heart disease reach adulthood ( Mandalenakis et al ). The largest leap in survival has been observed among cases with the most complex malformations. Indeed…

…Purkinje system) Preexisting AV block, bundle branch block or fascicular block may become worse. Particularly, the degree of AV block may increase. QRS complex QRS…

…First degree AV block with wide QRS complex First degree AV block with normal QRS complex (QRS duration <0.12 s) is localized in the…

…atrial rate (beats/min)? P waves should precede every QRS complex and the P wave should be positive in lead II. Common findings Sinus rhythm …

…However, a growing body of science suggests that essential hypertension is a multifactorial disease caused by a complex interplay between genes and environment. Industrialization and…

…in chronological order: Heart rate Rhythm P wave PR interval QRS complex ST segment T wave U wave QT (QTc) interval Pediatric and neonatal electrocardiograms…

…sensed by the atrial lead and triggers ventricular stimulations. The QRS complex is wide due to ventricular depolarization proceeding outside the conduction system. Figure 4…

…It may be broken, as in Figure 1 . Any type of infarction may cause pathological R wave progression. However, the specificity for pathological R wave…

…stimulate both ventricles simultaneously). A tachycardia with Q wave or QS complex in lead I suggest that the tachycardia is caused by the CRT device.

…conduction system. This slow propagation leads to a delayed and abnormal activation sequence of the right ventricle, resulting in a prolonged and abnormal QRS complex…

…the left ventricle is many times larger than the right ventricles, which is why the QRS complex is dominated completely by left ventricular vectors. Hence…

…each successive beat until a P wave fails to conduct, resulting in a dropped QRS complex. Second degree AV block Mobitz type II is characterized…

…starts discharging. Less than 3 consecutive beats (or from a latent pacemaker (or any other ectopic focus) are referred to as escape beats. Three or…

…ventricular rate between 50 and 100 beats/min. P wave with constant morphology preceding every QRS complex. The P wave is positive in lead II…

…circumferential shortening (Figure 1C). Left ventricular function depends on a complex interaction between the muscle fibers in these layers, which collectively produces a highly efficient…

…on concordance/discordance and Figure 1 ). If the T wave and the QRS complex head in opposite directions, the T wave is said to be…

…ventricular fibrillation. Cardioversion : Use of synchronized electric shock (i.e. a shock synchronized to the QRS complex). Typically used to treat atrial fibrillation, ventricular tachycardia…

…wave, QRS complex or T wave can be seen. This is pathognomonic (unique) to ventricular fibrillation and must not be confused with any other arrhythmia…

…seconds). The QRS complex is wide simply because the ectopic impulses that cause these rhythms spread partially or entirely outside of the ventricular conduction system…

…Reversal : : Warfarin Prothrombin complex concentrate (dose by INR and weight) plus vitamin K 10 mg IV Dabigatran Idarucizumab (Praxbind) Apixaban, rivaroxaban, edoxaban Prothrombin complex concentrate…