Non-invasive electrophysiological evaluation of calcium antagonist long-term therapy.
The evaluated effects of oral administration of verapamil, diltiazem, and nifedipine in patients with first degree A-V block by using a new noninvasive technique: signal averaged ECG. The study group consists of 5 females and 3 males ranging from 52 to 70 years old. All patients showed a first degree A-V block at surface ECG and an abnormal A-V time (suprahisian lengthening) during signal averaged ECG (SAECG). Verapamil 240 mg/daily, diltiazem 180 mg/day and nifedipine 30 mg/day were given separately for a week followed by a wash out period of 5 days before giving next drugs. An ECG and SAECG were performed before and after every administration. PR, A-H and H-V interval were evaluated in every recording. Verapamil and diltiazem induced a significant lengthening of A-V conduction (PR increase was 15.4% and 15.1%, respectively). No significant modification appeared after nifedipine. Our data, using a noninvasive technique, agreed with values of previous invasive evaluations. We suggest precaution in using verapamil and diltiazem in patients with BAV 1 degree and advise a selective use of calcium antagonist therapy.
1st Medical Clinic, 2nd School of Medicine, University of Naples, Italy.
L
L
Adinolfi
B
B
Golia
A
A
Montano
M
M
Marino
S
S
Napolano
F
F
Mazza
D000368:Aged; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D004110:Diltiazem / Q000627:therapeutic use; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000627:therapeutic use; D014700:Verapamil / Q000627:therapeutic use
D002121:Calcium Channel Blockers; D014700:Verapamil; D004110:Diltiazem; D009543:Nifedipine