Mortality is not increased with inferior infarction associated with right ventricular infarction and atrioventricular block.

BACKGROUND

Little information is available about the relation between right ventricular infarction (RVI) and the presence of atrioventricular block. Thus, the objective of this study was to analyse a possible correlation between the conditions, which are frequently associated with inferior acute myocardial infarction (AMI).

METHODS

We studied 107 patients with inferior AMI, of whom 49 had RVI, assessed by ST-segment elevation in right precordial leads (V3R-V4R) and by technetium-99m (99mTc) pyrophosphate scintigraphy. The diagnosis of atrioventricular block was made by continuous ECG monitoring during the first week of admission.

RESULTS

The patients were divided into two groups: group A with RVI and group B with isolated inferior AMI. These groups were similar regarding sex, age, coronary risk factors, and time from the onset of precordial pain to hospital admission. Group A had a predominance of atrioventricular block (61.2 versus 15.5%, P < 0.0004), peak creatine kinase MB (82.5 +/- 22.4 versus 65.2 +/- 25.1 IU/l, P < 0.05), congestive heart failure or cardiogenic shock (57.1 versus 18.9%, P < 0.002), and proximal right coronary artery occlusion (80.4 versus 25.0%, P < 0.001). Non-Q-wave infarction was more frequent in group B patients (14.2 versus 34.4%, P < 0.01). The mortality rate was similar in the two groups (12.2 versus 13.7%).

CONCLUSIONS

These data suggest that infarction extension from inferior wall to the right ventricle may be related to the development of atrioventricular block and does not increase mortality.