J Korean Geriatr Soc.  2002 Dec;6(4):311-319.

Electrocardiographic Diagnosis of Posterior Myocardial infarction using Posterior Chest Leads V7-9: Differences by Age

• Shin YW

Abstract

BACKGROUND: In patients with acute posterior myocardial infarction, the standard 12 leads electrocardiogram is often nondiagnostic, but posterior chest leads(V7 to V9) are expecting to identify those patients with posterior involvement. And so the meaning of posterior chest leads for detecting posterior infarction needs to determine, especially in the elderly with often nondiagnostic routine electrocardiogram.
METHODS
We studied eighty-four patients(aged 61+/-10 years, 61 men and 23 women) with acute myocardial infarction who had right coronary or left circumflex artery occlusion angiographically. All patients had technetium-99m pyrophosphate myocardial imaging and 2D echocardiographic imaging within 48 hours after admission to establish the diagnosis of acute posterior infarction. Patients were analyzed to determine on the diagnostic meaning of posterior chest leads and routine electrocardiogram in detecting posterior infarction.
RESULTS
The overall sensitivity of posterior chest leads, especially of lead V9 in detecting acute posterior myocardial infarction were 86.3%(69/80) with ST-segment elevation and 87.5%(70/80) with the appearance of pathologic Q waves. The 4 patients with lateral infarction were no changes in post chest leads. Left bundle branch block, artificial pacemaker rhythm, WPW syndrome, old anterior myocardial infarction. hypertrophy of left ventricle with strain pattern, and small infarction were a obstacle to detect posterior involvement with posterior chest leads. There are no significant age-associated differences in elderly patients for detecting posterior involvement with posterior chest leads.
CONCLUSION
Posterior chest leads(V7-9), especially lead V9 are a very sensitive and useful tool for diagnosis of posterior infarction, with no age associated differences.

MeSH Terms

Aged
Arteries
Bundle-Branch Block
Diagnosis*
Echocardiography
Electrocardiography*
Heart Ventricles
Humans
Hypertrophy
Infarction
Male
Myocardial Infarction*
Pacemaker, Artificial
Thorax*
Wolff-Parkinson-White Syndrome