…multidisciplinary heart team, including an interventional cardiologist and cardiac surgeon, is recommended when both revascularization strategies are feasible, particularly in complex multivessel or left main…

…or selectively after initial medical treatment. The presence of ST segment changes or a positive troponin assay identifies patients in whom an invasive strategy is…

…could enhance the score's predictive accuracy. The SYNTAX Score remains a cornerstone in the management of complex CAD, providing a structured approach to revascularization…

…of long term outcomes after revascularization. It incorporates both anatomical (from the original SYNTAX Score) and clinical variables (e.g., age, sex, renal function, left…

…third vector: the ventricular free wall The vectors resulting from activation of the ventricular free walls is directed to the left and downwards ( Figure 7 )…

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

…The QRS complex appears if the atrial impulse is conducted to the ventricles. Because the impulse enters the ventricles through the bundle of His (which…

…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)…

Arrhythmias and arrhythmology ECG Diagnosis and management of narrow and wide complex tachycardia All clinically significant supraventricular and ventricular tachyarrhythmias have been reviewed in previous…

…the left ventricle is many times larger than the vector generated by the right ventricle, the QRS complex is actually a reflection of left ventricular…

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…

…and clinical presentation of VT, with a deep dive into the underlying etiologies ranging from benign idiopathic variants to complex scar related and genetic substrates…

…specifically classified by the 2022 AHA/ACC/HFSA and 2021/2023 ESC guidelines as HF with a left ventricular ejection fraction (LVEF) of ≤40% [14…

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

…even in patients with left ventricular dysfunction, though those with depressed ejection fraction should receive it with great caution due to the risk of hypotension…

…a chronic, relapsing and biologically complex disease characterized by excessive accumulation of adipose tissue. It is an important cause of cardiovascular disease (CVD), cardiovascular risk…

…complex clinical syndrome characterized by the cardinal symptoms and signs of heart failure (HF) in the presence of a left ventricular ejection fraction (LVEF) of…

…the QRS complex in V1–V2 resembles a left bundle branch block (i.e negative QRS) V1 : The initial portion of the QRS complex is…

…injury, accelerates atherosclerosis, increases myocardial oxygen demand, and may worsen ischemia in patients with obstructive coronary disease. It is also the most prevalent antecedent of…

…the left ventricle. QRS duration QRS duration is the time duration from the start to the end of the QRS complex. A short QRS complex…

…it is asked of a patient who is haemodynamically stable enough for there to be time to ask it. Indications Wide complex tachycardia where ventricular…

…complete heart block without current symptoms, alternating bundle branch block in acute anterior infarction, and before drugs or procedures with a known risk of bradycardia…

…Note that 10% of wide complex tachycardias actually originate from the atria but the QRS complexes become wide due to abnormal ventricular depolarization (e.g…

…characterized by a significant reorganization of the activation and recovery patterns within the left ventricle, resulting in a widened QRS complex and secondary ST T…

…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…

Arrhythmias and arrhythmology Procedurer Lathundar Electrical cardioversion is the delivery of a precisely regulated electrical shock to terminate a tachyarrhythmia, and it encompasses both synchronized…

…to moderate exacerbation of asthma symptoms. Adenosine should be used with caution in patients with obstructive lung disease or asthma. Irregular wide complex tachycardia (absolute…

…The contemporary understanding of AF has evolved significantly; it is no longer viewed merely as an electrical anomaly but as a progressive, complex atrial myopathy…

…with the use of the ejection fraction is that it only assesses systolic function . Research in recent years has demonstrated that left ventricular diastolic function…

…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…

…high vagal tone. These individuals have developed a highly efficient left ventricle, capable of generating sufficient cardiac output at low heart rates. During vasovagal syncope…

…220 msec. The PR segment is the flat line between the end of the P wave and the start of the QRS complex. The PR…

…P wave precedes every QRS complex; the PR interval is constant and the P wave is positive in lead II. Causes of bradyarrhythmia: sinus bradycardia…

…Method of interpretation Heart rate Heart rhythm The P wave The PR interval The QRS complex The ST segment The T wave The U wave…

…platelet rich because they form under high shear conditions. Disruption of an atherosclerotic plaque or injury associated with PCI exposes thrombogenic material, promoting platelet activation…

…complex in III and aVF (with QRS duration <0.12 seconds), provided that other causes of right axis deviation have been excluded. Causes of left…

…Net negative QRS complex in leads I and II. Heart axis deviation: right axis deviation (RAD) and left axis deviation (LAD) Causes of right axis…

…positive QRS complex should be followed by a positive T wave, and vice versa ( Figure 17 ). Otherwise there is discordance (opposite directions of QRS and…

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

…QRS complex), which has much stronger electrical potentials. Cell types in electrocardiology For the purpose of this discussion it is important to distinguish between two…

…with the most complex malformations. Indeed, even the most severe malformations have become routine practice. The treatment repertoire includes surgery, catheter interventions, and medical therapies…

…become worse. Particularly, the degree of AV block may increase. QRS complex QRS duration becomes prolonged. ST segment ST segment depression may develop. T wave…

…QRS complex First degree AV block with normal QRS complex (QRS duration <0.12 s) is localized in the AV node in 90% of the…

…Note that 10% of wide complex tachycardias actually originate from the atria but the QRS complexes become wide due to abnormal ventricular depolarization (e.g…

…a multifactorial disease caused by a complex interplay between genes and environment. Industrialization and a Western lifestyle are strongly related to the development of hypertension…

…P wave PR interval QRS complex ST segment T wave U wave QT (QTc) interval Pediatric and neonatal electrocardiograms differ markedly – in terms of rhythm…

…in left bundle branch block (LBBB), which explains why paced QRS complexes are similar to the QRS morphology during LBBB. Stimulation in other regions of…

…amplitude of the R waves. This is believed to be due to delayed (and thus electrically unopposed) depolarization in the ischemic area. Fragmented QRS complex…

…set to be triggered by the atrial impulse. Another cause of pacemaker mediated tachycardia is endless loop tachycardia, which also depends on the ventricular stimulation…

…depolarizes after the left ventricle, allowing its electrical vectors to become evident. These vectors manifest in the later part of the QRS complex as an…

…1. ECG changes seen in left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH). The electrical vector of the left ventricle is enhanced in LVH…

…as a gradual prolongation of the PR interval with each successive beat until a P wave fails to conduct, resulting in a dropped QRS complex…

…QRS complex. This rhythm is referred to as a junctional rhythm . The His Purkinje network : All these fibers possess automaticity with an intrinsic rate of…

…every QRS complex. The P wave is positive in lead II. Figure 1 (below) shows normal sinus rhythm at a paper speed of 25 mm…

…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…

…concordance between QRS complex and ST T segment. The transition from ST segment to T wave should be smooth. The amplitude of the T wave…

…the phase of the cardiac cycle) to terminate ventricular fibrillation. Cardioversion : Use of synchronized electric shock (i.e. a shock synchronized to the QRS complex)…

…ECG features of ventricular fibrillation The ECG shows irregular waves with varying morphology and amplitude. No P wave, QRS complex or T wave can be…

…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…

…rivaroxaban, edoxaban Prothrombin complex concentrate, consider within 15 hours of the last dose. Andexanet alfa where available Low molecular weight heparin Protamine has only a…