Atrial arrhythmias are heart rhythm disorders in which the producing mechanism is in the atria or the sinus node or in an ectopic focus located outside the sinus node or occur through a reentry mechanism at this level.
Atrial extrasystolesare premature contractions of the heart and are produced by impulses coming from ectopic focus located in the walls of the atria. Ectopic impulses activate the atria in different ways than the sinus impulse, which reflect different P waves on the electrocardiogram.
Atrial extrasystoles may occur in people with a healthy heart (if so they do not have a pathological significance), in patients with heart disease (ischemic heart disease, heart failure) in patients with COPD and hypoxemia (due to hypertension of the small circulation) and in patients with hyperthyroidism. Atrial extrasystoles can precede the installation of supraventricular (atrial) tachycardias, flutter and atrial fibrillation, especially in chronic forms.
Digitalis intoxication can be also the cause and can frequently announce the installation of an atrial tachycardia with block. In myocardial infarction, atrial extrasystoles may be a sign of atrial infarct. Emotion, fatigue, coffee, tobacco, are precipitating factors of atrial extrasystoles, especially in healthy individuals.
Atrial extrasystoles are generally asymptomatic, symptoms usually are resumed to a feeling of discomfort in the chest which is quite annoying, and palpitations. When they occur in bursts they are accompanied by paleness, anxiety, sweating, fainting, and even shortness of breath. Physical signs consist of irregular peripheral pulse and abnormal heartbeat succession.
Atrial extrasystoles causes:
- Atrial extrasystoles may occur in normal people without any patologic semnification. The risk of having atrial extrasystoles increases with age.
- Heart disease like myocardial ischemia (angina pectoris), myocarditis (heart muscle inflammation), dilated or hypertrophic cardiomyopathy, mitral valve prolapse
- Metabolic Disorders like hypokalemia (low potassium levels in the blood), hypoxia (low oxygen levels in blood), hypomagnesaemia (low amount of magnesium in the blood), hypercalcemia.
- Endocrine: hyperthyroidism ( secretion of thyroid hormones is increased)
- Medications: digoxin, theophylline, tricyclic antidepressants
- Different exciting substance abuse like coffee, tea, alcohol, cocaine, amphetamines
- Acute infection
- Hiatal hernia (herniation of the upper part of the stomach into the chest cavity)
- After surgery