what is sinus bradycardia?

Question

I need info on possible hypocalcemia or t-u fusion, minor i.v. conduction defect

Answer 1

Sinus bradycardia can be defined as a sinus rhythm with a resting heart rate of 60 beats/minute or less. However, few patients actually become symptomatic until their heart rate drops to less than 50 beats/minute. The action potential responsible for this rhythm arises from the sinus node and causes a P wave on the surface ECG that is normal in terms of both amplitude and vector. These P waves are typically followed by a normal QRS complex and T wave.

Answer 2

A regular but unusually slow heart beat (60 beats/minute or less at rest). Sinus bradycardia can be the result of many things including good physical fitness, medications, and some forms of heart block. Low blood calcium makes the nervous system highly irritable with tetany (spasms of the hands and feet, muscle cramps, abdominal cramps, and overly active reflexes). Chronic hypocalcemia contributes to poor mineralization of bones, soft bones (osteomalacia) and osteoporosis.

What are the causes of slow heart rates?



Abnormally slow heart rates (bradycardias) can result from diseases affecting the SA node, the conduction tissues, and the AV node. Sick sinus syndrome is a disease wherein the SA node cannot generate signals frequently enough to maintain adequate heart rate. Heart blocks are conditions where diseases (such as heart attacks) or degeneration (due to processes such as aging) of the AV node and/or the conduction tissues impair the transmission of signals from the SA node to the heart muscles.



Some medications can cause bradycardia. Examples of these medications include calcium channel blockers such as verapamil (Calan) and beta-blockers such as propanolol (Inderal) and digoxin (Lanoxin). These medications can also aggravate bradycardias in patients with existing diseases of the SA node, AV node, and other parts of the heart's conduction system.