Normal Sinus Rhythm refers to a heart rhythm originating from the sinoatrial (SA) node at a rate of 60-
100 beats per minute (BPM), following the normal conduction pathway of the cardiac cycle.
Sinus Bradycardia occurs when the SA node fires at a rate of less than 60 BPM, while still following the
normal conduction pathway. This can be normal in athletes.
Symptomatic Sinus Bradycardia presents with symptoms such as pale, cool skin, hypotension, weakness,
angina, dizziness or syncope, confusion or disorientation, and shortness of breath.
Treatment for symptomatic Sinus Bradycardia includes administering atropine or considering pacemaker
therapy. If the bradycardia is caused by medications, these may need to be held, discontinued, or
adjusted.
Sinus Tachycardia involves the same conduction pathway as normal sinus rhythm but with an increased
discharge rate from the SA node, resulting in a heart rate of 101-200 BPM. This can be due to vagal
inhibition or sympathetic stimulation.
Symptoms of Sinus Tachycardia include dizziness, dyspnea, and hypotension due to decreased cardiac
output. Increased oxygen consumption may occur due to the elevated heart rate. Patients with coronary
, artery disease (CAD) or acute myocardial infarction (AMI) may also experience angina or an increase in
infarction size.
Sinus Tachycardia Tx ✔️The underlying cause determines treatment, eg.) pain management if d/t pain.
In stable pts vagal manuevers can be attempted. Beta-adrenergic blockers
Atrial Flutter ✔️An atrial tachydysrhythmia identified by recurring, regular, sawtooth-shaped flutter
waves that originate from a single ectopic focus in the right atrium, less commonly, can occur in left
atrium.
Atrial Flutter S/S ✔️High venticular rate; loss of atrial 'kick'. Decreased CO, HF: esp in pts with
underlying heart disease, and increased risk of stroke.
Atrial Flutter Tx ✔️Coumadin, slow ventricular response by increasing AV block, calcium channel
blockers, beta-adrenergic blockers, electrical cardioversion, antidysrhythmia meds, and radiofrequency
catheter ablation.
Atrial Fibrillation ✔️Characterized by a total disorganization of atrial electrical activity due to multiple
ectopic foci resulting in loss of effective atrial contraction. May be paroxysmal or persistant (+7 days).
Most common dysrhythmia.