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[Effect of glycerol trinitrate on R-amplitude in patients with chronic ischemic heart disease]

W Teichmann1

  • 1Klinik und Poliklinik für Innere Medizin, Martin-Luther-Universität Halle/Saale.

Zeitschrift Fur Kardiologie
|January 1, 1989
PubMed

Insights

Glycerol trinitrate (GTN) reduced R-wave amplitudes in resting ECGs of coronary artery disease patients, suggesting it alleviates ischemia. This effect was not observed after bypass surgery.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Pharmacology

Context:

  • Coronary artery disease (CAD) is characterized by myocardial ischemia, which can manifest in electrocardiogram (ECG) abnormalities.
  • Elevated R-wave amplitudes in precordial leads have been observed in patients with CAD and angina pectoris.

Purpose:

  • To investigate the effect of glycerol trinitrate (GTN) on R-wave amplitudes in resting ECGs of patients with CAD.
  • To determine if GTN-induced changes in R-wave amplitudes correlate with ischemia and are altered by coronary bypass surgery.

Summary:

  • R-wave amplitudes (sigma R) were measured in 36 precordial ECG leads in 50 CAD patients and 35 controls before and after sublingual GTN (0.8 mg).
  • In CAD patients, GTN significantly decreased sigma R amplitudes (19.5 +/- 26.4 mm, p < 0.05), while controls showed a slight increase (18.7 +/- 16.2 mm, p < 0.05).
  • In 21 patients, this GTN-induced decrease in sigma R was not observed after coronary bypass surgery.

Impact:

  • These findings support the hypothesis that GTN can reduce enhanced R-wave amplitudes in resting ECGs, indicating a reduction in ischemia.
  • The study highlights the potential of ECG R-wave amplitude changes as a marker for assessing GTN's anti-ischemic effects.
  • The absence of the effect post-bypass surgery suggests a normalization of ischemic processes or altered drug response after revascularization.

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