More on the Impact of Right Ventricular Infarction
ABSTRACT & COMMENTARY
Source: Zeymer U, et al. Effects of thrombolytic therapy in acute myocardial infarction with or without right ventricular involvement. J Am Col Cardiol 1998;32:876-881.
Zeymer and colleagues performed a retrospective review of patients in the Hirudin for Improvement of Thrombolysis (HIT-4) study investigating the impact of right ventricular infarction (RVI) on the clinical course of individuals with acute inferior wall myocardial infarction (IWMI) treated with streptokinase within six hours of chest pain onset. In addition to the standard 12-lead ECG, patients were evaluated with the right-sided chest lead, RV4; RVI was diagnosed if RV4 ST segment elevation (STE) was greater than 0.1mV. IWMIs were described as small (inferior lead STE sum £ 0.8mV without precordial ST segment reciprocal depression [STD]) or large (sum > 0.8 mV and/or reciprocal precordial STD).
Five hundred twenty-two patients with IWMI were identified, with 169 patients (32%) experiencing RVI. Larger-sized infarcts were encountered more frequently in patients with RVI. Patients with RVI experienced in-hospital complications more often, including malignant tachyarrhythmia and reinfarction; importantly, bradyarrhythmias were not studied in the HIT-4 study. Overall mortality rates were similar considering the presence or absence of RVI, although cardiac mortality was higher in the RVI group. Independent predictors of 30-day cardiac mortality included increasing age, history of angina, larger IWMI, and elevated CPK (> than 12 times the norm); the presence of RVI was not an independent predictor of 30-day cardiac mortality.
Comment by William J. Brady, MD
Among patients with IWMI complicated by RVI, increased rates of both early complication and 30-day mortality were encountered. Zeymer et al conclude that the use of thrombolytic agents as acute revascularization therapy in the setting of acute IWMI should be questioned. They note that the presence of RVI by itself was not a marker of increased chance of poor outcome; patients with larger-sized infarcts—either with or without RVI—are more likely to achieve benefit in terms of reduced mortality and improved left ventricular function.
The reader must realize that such a treatment recommendation is based on this subset of patients with IWMI who were treated with streptokinase within six hours of onset. Until randomized trials of acute reperfusion therapies in IWMI patients with and without RVI are performed, such treatment statements cannot be fully supported. Rather, the clinician must approach each IWMI patient individually, considering issues such as comorbidity, infarct size, the presence of electrocardiographic reciprocal STD, and the occurrence of arrhythmic and nonarrhythmic complications, when making treatment decisions.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content