Bundle branch blocks (BBB) Bundle branch blocks are characterized by an interruption in ventricular conduction at the bundle of His, usually due to ischemia. The ventricles do not depolarize at the same time. RBBB affects the right ventricle while LBBB…

Sinus bradycardia is a heart rate of < 60 bpm, with a normal sinus rhythm

An atrioventricular (AV) nodal block is a conduction disorder that is characterized by an interruption between the sinoatrial node and atrioventricular node (PR interval), resulting in an elongation of the PR interval (> 0.2 sec). It is congenital in some…

Bradyarrhythmias are characterized by a heart rate of < 60 bpm

An arrhythmia is an abnormal heart rhythm due to a disruption in normal electrical conduction. Atrial fibrillation is the most common arrhythmia. Main classification of arrhythmias Classification Description Examples Bradyarrhythmias HR < 60 bpm Supraventricular: atrial fibrillation, atriventricular nodal reentrant…

Sudden cardiac death is unexpected death from cardiac causes in persons without symptoms of heart disease or within one hour of the onset of symptoms. It frequently occurs in the morning hours and evening as the adrenergic system kicks in…

Wellen’s syndrome is a clinical syndrome characterized by biphasic or deep inversion of T waves in V2 – V3, in a patient with chest pain that has resolved. It is seen in critical stenosis of the left anterior descending artery…

Myocarditis is inflammation of the myocardium. Inflammation may cause severe, acute heart failure, which may require organ support or an emergency heart transplant in fulminant cases. The majority of cases are caused by viruses. It often occurs with pericarditis (myopericarditis).…

Syncope is a transient loss of consciousness due to global cerebral hypoperfusion that occurs with rapid onset, short duration, and spontaneous complete recovery. This definition excludes other causes of loss of consciousness, such as epilepsy. Reflex syncope is the most…