Nocturnal angina pectoris


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Overview
Nocturnal angina is the occurrence of anginal discomfort either during the early hours of sleep or during the early morning hours. It is speculated that onset during the early hours of sleep results in an increased venous return causing in discomfort whereas onset during the early morning hours results in an increased vascular tone causing discomfort.

Pathophysiology

 * Among patients who develop nocturnal angina within an hour or two of going to sleep, the mechanism of angina in this group of patients is likely to be an increase in venous return and hence increased intracardiac volume with a resulting increase in myocardial oxygen requirements.
 * Among patients who develop nocturnal angina in the early morning hours a primary reduction in coronary blood flow resulting from increased coronary vascular tone has been postulated as the potential underlying mechanism. It is further asserted that this particular form of nocturnal angina is related to the biological changes associated with different stages of the sleep cycle.

Symptoms
Two patterns of nocturnal angina are observed:
 * 1) Some patients experience angina within an hour or two after sleeping.
 * 2) Other group of patients with nocturnal angina experience chest discomfort much later, in the early hours of the morning.

Treatment

 * The treatment is the same as chronic stable angina.
 * If increased coronary vascular tone is felt to be the underlying mechanism, the calcium channel blockade may be of benefit.