Are an excessive number of permanent pacemakers being inserted?

ABSTRACTS

IMPLANTED AUTOMATIC BURST PACEMAKERS FOR TERMINATION OF VENTRICULAR TACHYCARDIA. John D. Fisher, MD, FACC, Seymour Furman, MD, FACC, Soo Gyum Kim, MD, Montefiore Hospital and Medical Center, Bronx, New York Automatic burst pacemakers for termination of ventricular tachycardia (VT) are needed because of three major limitations with manual systems, i.e., 1) syncope may occur before the pacemaker can be activated; 2) VT may exist ""noticed for long periods until hemodynamic decompensation occurs; 3) patients (pts) develop psychologic syndromes due to responsibilities of managing manual system*. We implanted automatic burst pacers in four VT pts; two Medtronic (Medt) 2404 and two Intermedics Cybertach (Cytach). The Medt units are custom prescription ""its with bursts at a fixed rate or adaptive as a % of the VT cycle length (CL). The Cytach is a programmable pacer with tachycardia criterion, burst rate Both pacers and duration, and other features adjustable. can be disarmed to work as ventricular demand pacer* only. # stimuli Pacer VT rate Burst rate Pt. 180-220 7 Medt (75% VT CL) 1 8 125-190 232 2 Medt 206 8 140-150 cytach 3 206 8 Cytach 140-155 4 Results: over a follow-up period of O-12 months there have been no major complications, no malfunctions, no evidence of inappropriate bursts, and no further Atria1 fibrillation with a hospitalizations for VT. rapid pulse led to disarming one unit which is rearmed I" carefully selected when needed for termination of VT. pts automatic burst pacemakers open new horizons for control of VT.

THE MANAGEMENT OF PAROXYSMAL FIBRILLATION ASSOCIATED WITH Elio Di Segni, MD; Herman 0. Elieser Kaplinsky, MD, FACC, General Hospital and Tel-Aviv

VENTRICULAR TACHYCAROIA AND THE LONG QT SYNDROME Klein, MD; Daniel David, MD; Department of Cardiology,Meir University, Israel.

Prolongation of the QT interval is known to be associated with repetitive paroxysms of a particular ventricular tachycardia called also “torsade de pointes”. It is a typical complication of quinidine but may occur in various other conditions. Antiarrhythmic medications are ineffective and treatment is empirical. We have utilised transvenous right ventricular endocardial pacing in 12 patients with marked prolongation of the QT interval suffering from bouts of ventricular tachycardia and fibrillation. In six patients the syndrome was due to quinidine. Acceleration of the heart rate resulted in immediate suppression of all arrhythmias. Pacing was continued until the condition producing the QT prolongation disappeared. In one case a permanent pacemaker was implanted as the QT prolongation was congenital and permanent. The actual QT interval was shortened by overdrive pacing in all patients (< 0.5 seconds) but the corrected QT interval remained prolonged (> 0.6 seconds). The arrhythmia was therefore clearly dependent upon the actual QT interval and overdrive pacing could suppress it by decreasing the actual interval without shortening the corrected interval. All 12 patients survived and in 11 pacing was discontinued following the return of both the actual and corrected QT intervals to normal. In conclusion, overdrive pacing is an

effective,

treatment brillation

safe, in

paroxysmal

associated

expeditious

and

ventricular with

prolongation

reliable

mode

tachycardia of

of

and the

fi-

QT inter-

val.

458

February 1980

The American Journal of CARDIOLOGY

WEDNESDAY, MARCH 72, 1980 AM CARDIAC PACEMAKERS 10:30- 12:oo RADIONUCLIDE ANGIOGRAPHIC EVALUATION OF LEFT VENTRICULAR PERFORMANCE DURING VENTRICULAR PACING Charles A. Boucher, M.D., FACC, Gerald M. Pohost, M.D., FACC, Frederick K. Pouli", M.D., H. William Strauss,M.D., Robert D. Okada, M.D., J. Warren Harthorne, M.D., FACC, Massachusetts General Hospital, Boston, MA. To determine the effect of ventricular pacing (VP) on global and regional left ventricular (LV) function, gated cardiac blood pool *can* were performed in 15 patients (pts) with permanent transvenous ventricular pacemakers. I" all, the heart rate during VP was within 15 beats/min of the rate during sinus rhythm (SR). LV ejection fraction (EF) was derived and the synchrony and synergy of LV WM was scored regional wall motion (WM) was evaluated. in 3 LV segments each in the anterior and left anterior oblique views on a 5 point scale from 3 = normal to -1 = dyskinesis. Ten pts had a normal (NL) EF (>.50) and 5 pts had a" abnormal (ABN) EF (~35). Seven of the pts with NL EF had scans both at rest and during exercise. At rest, NL pts had a small but statistically significant mea" decrease in EF of 0.03+.04 (+ 1 S.D.), pc.05, during VP, compared with SR. In addition, contraction became asynchronous, beginning in the anterolateral and posterobasal walls and ending at the apex. The septum, apex, and inferior walls showed significant reduction in WM during VP, compared with SR, whereas the anterolateral and posterobasal walls remained NL. During exercise, there was no longer a difference in EF between SR and VP, and the contraction pattern became "early synchronous. I" ABN pts, EF and WM were the same with SR and VP. 1) NL pts demonstrate reduction in In conclusion: global and regional LV function during VP at rest, but demonstrate no significant differences during exercise; 2) In ABN pts, there was no difference in EF and WM during VP, compared with SR.

ARE AN EXCESSIVE NUMBER OF PEt+.‘INENT PACEMAKERS BEING INSERTED? Atul B. Chokshi, M.D.; Howard S. Friedman, M.D., FACC; FACC; Balendu C. Vasavada, M.D.; Monte Malach. M.D., Sheldon J. Bieiche;, M.D. The Brooklyn Hospital and Downstate Medical Center (SUNY), Brooklyn, NY Almost 100,000 pacemaker generators were inserted in 1978 at an estimated cost of at least 500 million dollars. Between 1973 and 1976 permanent pacemaker(PP)insert at The Brooklyn Hospital increased by 71%. Accordinaly, it is our purpose to review our experience for this period to determine whether some of these PP may have been unnecessary and to show the impact of peer-review on reducing operations. The average age of patients was 73 such years ( range 24-95). The indications for a PP in 169 patients was sick-sinus syndrome in 92(54%),intraventricular conduction abnormality in 44(26%)and complete or advanced In 1976 heart block was the indiheart block in 28(17%). cation in only 8% of the patients. Of the 92 patients with sick-sinus syndrome IO were receiving alphamethyldopa and 29 digitalis and/or propranolol; thus, in 42% of the patients receiving a PP for bradycardia an iatrogenic cause may not have been excluded. Preliminary review of patients receiving a PP for indications other than heart block showed that in at least 22 ofl41(15.6%)symptoms persisted and that 23(16.3%)died less than I year after PP had been inserted. A mOre critical policy and the institution of a pacemaker-review committee which provided guidelines and a means for ongoing retrospective review produced a decline in PP insertions by 46% from 1976 in both 1977 and 1978. It is concluded that peer-review can improve patient selection and thereby result in a substanI’f our experience can be tial reduction in PP operations. extrapolated nationally, the result could be an estimated dol lars per year. health-care savings of $ of a bi I lion

Volume 45