Unstable angina with tachycardia: clinical and therapeutic implications.
We prospectively evaluated 19 patients with prolonged chest pain not evolving to myocardial infarction and accompanied with reversible ST-T changes and tachycardia (heart rate greater than 100 beats/min) in order to correlate heart rate reduction with ischemic electrocardiographic (ECG) changes. Fourteen patients (74%) received previous long-term combined treatment with nifedipine and nitrates. Continuous ECG monitoring was carried out until heart rate reduction and at least one of the following occurred: (1) relief of pain or (2) resolution of ischemic ECG changes. the study protocol consisted of carotid massage in three patients (16%), intravenous propranolol in seven patients (37%), slow intravenous amiodarone infusion in two patients (10%), and intravenous verapamil in four patients (21%) with atrial fibrillation. In three patients (16%) we observed a spontaneous heart rate reduction on admission. Patients responded with heart rate reduction from a mean of 125 +/- 10.4 beats/min to 84 +/- 7.5 beats/min (p less than 0.005) and an ST segment shift of 4.3 +/- 2.13 mm to 0.89 +/- 0.74 mm (p less than 0.005) within a mean interval of 13.2 +/- 12.7 minutes. Fifteen (79%) had complete response and the other four (21%) had partial relief of pain. A significant direct correlation was observed for heart rate reduction and ST segment deviation (depression or elevation) (r = 0.7527 and 0.8739, respectively). These patients represent a unique subgroup of unstable angina, in which the mechanism responsible for ischemia is excessive increase in heart rate. Conventional vasodilator therapy may be deleterious, and heart rate reduction in mandatory.
Sclarovsky
S
S
Israel and Ione Massada Center for Heart Diseases, Beilinson Medical Center; Petah Tikva, Israel.
Bassevich
R
R
Strasberg
Klainman
E
E
Rechavia
E
E
Sagie
A
A
Agmon
J
J
D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000787:Angina Pectoris / Q000150:complications*; D000789:Angina, Unstable / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011433:Propranolol / Q000627:therapeutic use; D011446:Prospective Studies; D013610:Tachycardia / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D014700:Verapamil / Q000627:therapeutic use
D011433:Propranolol; D014700:Verapamil; D000638:Amiodarone