Cardiac Rhythm — Complete

: An irregular and often rapid heart rhythm that can increase the risk of stroke or heart failure.

Cardiac rhythm is the regular pattern of your heartbeat, controlled by the heart’s internal electrical system. In a healthy adult at rest, this rhythm typically falls between 60 and 100 beats per minute (bpm). Normal Cardiac Rhythm cardiac rhythm

: A common, harmless variation where the heart rate slightly increases during inhalation and decreases during exhalation. : An irregular and often rapid heart rhythm

Your heart rhythm naturally fluctuates based on activity, stress, or sleep. However, it is considered abnormal (an arrhythmia) when it is inappropriately fast, slow, or irregular. : A fast resting heart rate exceeding 100 bpm. Bradycardia : A slow resting heart rate below 60 bpm. Normal Cardiac Rhythm : A common, harmless variation

: Ventricular contraction (bottom chambers pumping blood to the lungs and body). T Wave : Ventricular recovery (preparing for the next beat). Common Variations and Abnormalities (Arrhythmias)

: Atrial contraction (top chambers pumping blood to the bottom chambers).

A normal rhythm, known as , starts in the sinoatrial (SA) node—the heart's natural pacemaker. This signal travels through the heart in a specific sequence, which is visualized on an electrocardiogram (ECG) as the PQRST wave pattern: