Effects of long‐term transdermal nitrate treatment on left ventricular function in patients following myocardial infarction

.*First Department of Internal Medicine/Cardiology, County Hospital, Kecskemet, and *Department of Cardiology, University ofDebrecen, Debrecen, HungarySummaryBackground: Nitrates are widely used for the treatment ofmyocardial infarction (MI). The large megatrials (GISSI-3and ISIS-4) did not in fact demonstrate a significant decreasein mortality in the nitrate-treated group. However, examina-tion of the number of postinfarction angina episodes and theoccurrence of cardiogenic shock in the GISSI-3 study did re-veal significant decreases.Hypothesis: It was hypothesized that chronic nitrate treat-ment after an MI preserves left ventricular systolic and/or dias-tolic functions.Methods: Patients were divided into two groups: those re-ceiving chronic nitrate treatment for 6 months after an MI (n =30), and those without such treatment (n = 29). Echocardi-ography was performed 3, 14, 42, and 180 days after the in-farction. The changes in early diastolic and atrial contraction-related mitral valve inflow pattern and deceleration time wereassayed. Alterations in systolic, diastolic, and atrial reverseflow velocities in the pulmonary vein were measured, as wereejection fraction (EF), the number of registered angina epi-sodes, and the maximal ST-segment depression in response tothe stress test.Results: During the 6-month study period, the increase insystolic pulmonary venous flow velocity was significantlylarger in the nitrate group than in the controls. The decreases inthe velocities of the diastolic and the atrial reverse flow werealso more pronounced in the nitrate group than in the controls.The EF was improved only in the nitrate group. Examinationof the maximal ST-segment depression in response to thestress test revealed a significant decrease in the nitrate grouponly. There were no significant differences between the twogroups in the number of registered angina episodes or mitralinflow pattern.Conclusions: The study showed that prolonged nitratetreatment after an MI may help preserve diastolic left ventric-ular function.Key words: nitrate, myocardial infarction, diastole, pulmon-ary veinsIntroductionThe administration of nitrate compounds for the treatmentand prevention of angina pectoris has been known for morethan 100 years. The vasodilatory effects of such compoundsare more pronounced on the venous system. Consequently,they reduce preload more substantially than afterload. The va-sodilatory effects lead to reductions in (1) left ventricular (LV)filling pressure, (2) dilatation of the ventricle, and (3) systolicwall tension.