…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…

…Troponin I is highly specific for myocardial injury. Interpretation of troponin T is more complex because injured skeletal muscle may express proteins detected by some…

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

…rare (Naxos disease, Carvajal syndrome). The prevalence of ARVC is between 0.02 and 0.05% in Europe (Corrado et al). ARVC is more malignant…

…However, refrain from rescue breaths to mitigate the risk of potential contaminants endangering the rescuer. Contact expertise Contact your national or regional poison control centre…

…and syndrome: from ECG criteria to management Although the early repolarization pattern has been recognized for almost 50 years, it is still one of the…

…to the QRS morphology during LBBB. Stimulation in other regions of the ventricle may result in a different QRS morphology. If the lead tip is…

…lower case letters (q, r, s). Figure 5 shows examples of naming of the QRS complex. Net direction of the QRS complex The QRS complex…

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

…the bundle of His (which means that both bundle branches will conduct the impulse to each respective ventricle) the QRS complex is normal (i.e…

…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…

…in order to give the reader firm knowledge of normal findings , normal variants (i.e less common variants of what is considered normal) and pathological…

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…

…Torsades de Pointes in Long QT Syndrome) [1] . Underlying Etiologies The etiology of VT is broadly dichotomized into structural heart disease (SHD) and structurally normal…

…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…

…failure (HF) is a complex clinical syndrome characterized by symptoms and signs resulting from structural or functional impairment of ventricular filling or ejection of blood…

…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…

…low back pain Symptoms of type 2 diabetes or metabolic syndrome Depression, low self esteem or body image disturbance The number and severity of obesity…

…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…

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…

…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…

…clip the hair — small cuts cause burning pain. 2. Position the pads, preferably anteroposteriorly : one anteriorly over the praecordium to the left of the sternum…

…12 s : Pre excitation (WPW syndrome). Second degree AV block Mobitz type I (Wenckebach block) : repeated cycles of gradually increasing PR interval until an atrial…

…pathology) [3] Absence of Q waves in I, V5, and V6 [3] ST T Waves Usually opposite in direction to the QRS complex [3] Not…

…ischemia Cardiomyopathy Bradycardia Hypothyroidism Hypothermia A separate chapter discusses Long QT syndrome (LQTS). A complete list of drugs causing QT prolongation can be found here…

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…

…an accessory pathway [see Wolff Parkinson White Syndrome]); blocking AV node conduction may result in accelerated transmission of atrial impulses to the ventricles and thus…

…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…

…QT syndrome (LQTS) & ventricular arrhythmias (torsade de pointes) due to prolonged QT interval The QT interval is the time interval from the beginning of the…

…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…

…12 s: pre excitation (WPW syndrome). Second degree AV block, Mobitz I (Wenckebach): repeated episodes with progressive lengthening of the PR interval until an atrial…

…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…

…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…

…infarction rates. Clinical presentation and symptoms The clinical presentation is determined primarily by the ACS syndrome and the haemodynamic consequences of the culprit lesion. Patients…

…particularly in complex multivessel or left main disease. Clinical presentation and symptoms The clinical presentation of multivessel CAD varies from stable angina or exertional limitation…

…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…

…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…

…T wave represents a difficult but fundamental part of ECG interpretation. The normal T wave in adults is positive in most precordial and limb leads…

…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…

…with ventricular depolarization (i.e. QRS complex), which has much stronger electrical potentials. Cell types in electrocardiology For the purpose of this discussion it is…

…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…

…AV block I, or AV block 1. Before proceeding, it is recommended to review the basic concepts of AV blocks (refer to Introduction to AV…

…12 s : Pre excitation (WPW syndrome). Second degree AV block Mobitz type I (Wenckebach block) : repeated cycles of gradually increasing PR interval until an atrial…

…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…

…complex with more than 1 R wave and/or notch in the descending limb of the R wave and/or notch in the descending limb…

…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.

…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…

…V1–V3. The ST T segment is usually discordant to the QRS complex. V5, V6, I and aVL displays smaller R waves than normal. Along…

…complex. Second degree AV block Mobitz type II is characterized by sporadically occurring blocks, without the Wenckebach phenomenon. Second degree AV block Mobitz type I…

…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…

…the slope of the descending limb is slightly steeper than the ascending limb. A rather detailed reference regarding the direction of T waves follows: I…