…underlying coronary atherosclerotic process. Their clinical effects therefore occur within the broader framework of guideline directed medical therapy and secondary prevention. PCI treats focal stenotic…

…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…

…II Anatomical SYNTAX Score : Derived from the original SYNTAX Score, which evaluates the complexity of coronary lesions. Clinical Variables : Age : Older patients have a higher…

…Regardless of which waves are visible, the wave(s) that reflect ventricular depolarization is always referred to as the QRS complex . Naming of the waves…

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…

…depolarization (activation). The PR interval is the distance between the onset of the P wave to the onset of the QRS complex. The PR interval…

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…

…Consequently, current guidelines recommend a 3 generation family history and consideration of genetic testing for all patients with non ischemic HFrEF. Toxic and infiltrative causes…

…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…

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…

…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…

…under guideline directed medical therapy (GDMT). These patients must be managed as having HFrEF, as their underlying pathophysiology, trajectory, and risk of relapse upon GDMT…

…SVT) with wide QRS complex. The algorithm entails 5 criteria, which are tested sequentially (Figure 1). Figure 1. Flowchart of Brugada's algorithm for distinguishing…

…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…

…QRS complex, ST segment, T wave and QT interval This video is accompanied by the detailed article The normal electrocardiogram (ECG). A brief summary of…

…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…

…a widened QRS complex and secondary ST T wave abnormalities [7]. Diagnostic Criteria The diagnostic requirements for LBBB vary by the stringency of the criteria…

…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…

…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…

…waves with constant morphology preceding every QRS complex. P wave is positive in limb lead II. Normal (physiological) causes of sinus bradycardia Sinus bradycardia (SB…

…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…

…lead II. Extreme axis deviation (–90°to 180°) : Net negative QRS complex in leads I and II. Figure 2. The direction of the QRS complex. Axis…

…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…

…the P wave. In ventricular pacing, the stimulation artifact precedes the QRS complex. Two artifacts are seen if both chambers are paced. The stimulation artifact…

…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…

…part of the QRS complex as an R’ wave (pronounced "R prime"), which is directed anteriorly and rightward. Due to the abnormal depolarization sequence of…

…LVH) and right ventricular hypertrophy (RVH). The electrical vector of the left ventricle is enhanced in LVH, which results in large R waves in left…

…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…

…a complex interaction between the muscle fibers in these layers, which collectively produces a highly efficient pumping mechanism. Figure 1A 2C. The orientation of myocardial…

…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…