A sinus arrhythmia is an irregular heartbeat that's either too fast or too slow. One type of sinus arrhythmia, called respiratory sinus arrhythmia, is when the heartbeat changes pace when you inhale and exhale. In other words, your heartbeat cycles with your breath. When you breathe in, your heart rate increases.

1. SINUS ARRHYTHMIA

2.  Sinus arrhythmia is the variation in
heart rate is often synchronized with
breathing, slowing with expiration
and accelerating with inspiration.

3.  Rate- slows with expiration,
accelerates with inspiration
 Rhythm-irregular
 P waves-normal
 PR interval- not affected
 QRS complex- not affected
 QT interval- longer
 Rate varies with respiration
cyclical, irregular rhythm,uniform

4.  CAUSES:-
 Exercise
 Mental stress
 Respiration
 Blood pressure regulation
 Thermoregulation
 Actions of the renin-angiotensin
system

5.  Circadian rhythms
 Aging
 Diabetes
 Alcoholic cardiomyopathy
 Dizziness or syncope in excessively
long pauses