Prinzmetal’s angina and atrioventricular conduction disorders

ECG 3A: Atrial sinus activity; third degree atrioventricular block, atrioventricular dissociation, junctional escape rhythm (narrow QRS); ST-segment elevation in the inferior leads (subepicardial lesion); reciprocal depression in leads I, aVL;

ECG 3B: Tracing recorded 30 seconds after the first tracing; regression of the elevation amplitude; type 2:1 second degree atrioventricular block;

ECG 3C: Tracing recorded 30 seconds after the second tracing; regression of the amplitude of the elevation; second degree Wenckebach-type atrioventricular block at the beginning of the tracing followed by first degree atrioventricular block (long PR interval);

ECG 3D: Tracing recorded 30 seconds after the previous tracing; regression of the amplitude of the elevation; persistence of a slightly prolonged PR interval;

ECG 3E: Tracing recorded 30 seconds after the previous tracing; complete normalization of the tracing;

Comments: The prognosis of a Prinzmetal’s angina is favorable even if, as on these tracings, a spasm can be complicated by the occurrence of a rhythm disorder or a conduction disorder which can be accompanied by a syncope or sudden death. Some cases of first, second or third degree atrioventricular block have been described in the literature from 12-lead or long-duration ECG-Holter tracings. Conduction disorders occur preferentially during a spasm of the right coronary artery, given the junctional location of the block (ischemia of the branch supplying the atrioventricular node).

The dynamic pattern observed in this patient is characteristic of a nodal disease with successive demonstration of a complete atrioventricular block with narrow QRS (junctional escape), 2:1 block, Wenckebach pattern followed by first degree atrioventricular block (very long PR).

The effect of maximum medical treatment on the occurrence of conduction disorders may be insufficient, involving the need for implantation of a pacemaker even if there are no established expert recommendations in this setting.

Take-home message: The most common occurrence of an atrioventricular block in a Prinzmetal’s angina is a spasm of the right coronary artery with nodal localization of the block.