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The effect of isosorbide dinitrate on exertional hypotension in old myocardial infarction
Insights
Oral isosorbide dinitrate (ISDN) improved exertional hypotension in patients with old myocardial infarction (OMI). ISDN favorably affected exercise-induced ischemia and left ventricular dysfunction, correcting suppressed blood pressure responses during exercise.
Area of Science:
- Cardiology
- Clinical Medicine
- Pharmacology
Background:
- Old myocardial infarction (OMI) can lead to exertional hypotension.
- Patients with OMI often exhibit multivessel disease and severe left ventricular dysfunction.
- Exercise-induced ST depression or angina indicates myocardial ischemia in OMI patients.
Purpose of the Study:
- To investigate the effect of oral isosorbide dinitrate (ISDN) on exertional hypotension in OMI patients.
- To assess ISDN's impact on exercise-induced myocardial ischemia and blood pressure response.
- To evaluate ISDN's efficacy in patients with varying degrees of left ventricular dysfunction.
Main Methods:
- Treadmill exercise tests were performed on patients with OMI.
- Systolic blood pressure (SBP) response to exercise was monitored before and after 5 mg oral ISDN.
- Patients were categorized into groups based on the presence of ST depression or angina during exercise.
Main Results:
- ISDN improved blood pressure response in OMI patients with exertional hypotension.
- In patients without exercise-induced ischemia (Group I), ISDN decreased SBP at matched workload.
- In patients with ischemia (Group II), ISDN did not alter SBP, and the pressure change was greater than in Group I.
Conclusions:
- Oral ISDN can correct exertional hypotension in OMI.
- ISDN's benefits stem from mitigating exercise-induced myocardial ischemia and improving left ventricular dysfunction.
- The drug favorably influences the suppressed pressure response to exercise in OMI patients.
Abstract:
Four patients with old myocardial infarction (OMI) revealed exertional hypotension in the treadmill exercise test. All had a multivessel disease, severe left ventricular dysfunction and exercise-induced ST depression or angina to indicate additional myocardial ischemia. After 5 mg of oral isosorbide dinitrate (ISDN), the response of blood pressure was improved with a delayed onset of ST depression or angina. To confirm the effect of ISDN on the pressure response to exercise, 26 patients with OMI were further studied. In patients without ST depression and angina (Group I), the systolic blood pressure (SBP) at the matched work load was significantly decreased after ISDN. However, in patients with ST depression or angina (Group II), SBP at the matched work load was not altered after ISDN. The increment of change in SBP due to ISDN, namely from the resting level to the matched work load, was significantly larger in Group II than in Group I. In addition, the patients with marked left ventricular dysfunction in Group I revealed a more change in SBP due to ISDN than the others in Group I. It was concluded that exertional hypotension or suppressed pressure response of OMI could be corrected by 5 mg of oral ISDN due to its favorable effects on the exercise-induced myocardial ischemia and preexisting left ventricular dysfunction.