CLINICAL MEDICINE

Detailed explanation-1: -During sinus rhythm, every heartbeat you have starts in the sinoatrial (SA) node, a cluster of electrically active cells near the top of your heart. The SA node (also known as the sinus node) is your heart’s natural pacemaker and generates the electrical current that makes your heart muscle squeeze.

Detailed explanation-2: -The SA node is considered the pacemaker of the heart. Its electrical signals normally cause the atria of an adult’s heart to contract at a rate of about 60 to 100 times a minute.

Detailed explanation-3: -Key points about sinus bradycardia Sinus bradycardia is a kind of slow heartbeat. It happens when the sinoatrial node fires less than 60 times per minute. In some cases, sinus bradycardia is normal.

Detailed explanation-4: -Sinus bradycardia is a cardiac rhythm with appropriate cardiac muscular depolarization initiating from the sinus node and a rate of fewer than 60 beats per minute (bpm). The diagnosis of this condition requires an ECG showing a normal sinus rhythm at a rate lower than 60 bpm.

Detailed explanation-5: -Sinus bradycardia occurs on an ECG when there is a normal upright P wave in lead II ― sinus P wave ― preceding every QRS complex with a ventricular rate of less than 60 beats per minute.