Clinical and hemodynamic comparison of VVI versus DDD pacing in patients with DDD pacemakers.

To identify better those subgroups of pacemaker recipients who will benefit from dual chamber pacing, 19 patients with DDD pacemakers that were physiologically paced were entered into a blinded, randomized protocol comparing long-term VVI versus DDD pacing. Patients were evaluated in each of the pacing modes for exercise performance, cardiac chamber size, cardiac output, functional status and health perception. Eight patients (42%) insisted on early crossover, from VVI to DDD pacing, after only 1.8 +/- 1.4 weeks because of symptoms consistent with pacemaker syndrome. Overall, 12 patients preferred DDD pacing and no patient preferred VVI pacing (p = 0.001). Percent fractional shortening (30 +/- 8 vs 24 +/- 6%, p = 0.009) and cardiac output (6.3 +/- 2.6 vs 4.4 +/- 2.2 liters/min, p = 0.0001) where significantly greater in the DDD mode. Exercise duration was greater during DDD compared with VVI pacing (11.3 +/- 3.7 vs 10.1 +/- 3.7 minutes, p = 0.006). However, it was only in the crossover subgroup that DDD pacing resulted in significant improvement in exercise performance and health perception compared with VVI pacing. This subgroup of patients was characterized by an intrinsic sinus rate of less than 60 beats/min (4/8 vs 0/11, p = 0.006), ventriculoatrial (VA) conduction (4/8 vs 1/11, p = 0.048), greater increase in exercise peak systolic blood pressure from VVI to DDD mode (21 +/- 12 vs 4 +/- 13 mm Hg, p = 0.02) and greater improvement in exercise capacity from VVI to DDD pacing (2.2 +/- 1.2 vs 0.6 +/- 1.4 minutes, p = 0.03) compared with the other 11 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Mitral balloon valvuloplasty for mitral restenosis after surgical commissurotomy.

Mitral balloon valvuloplasty was performed in 14 patients with recurrent mitral stenosis 16.9 +/- 1.8 years (range 6 to 30) after surgical commissurotomy. There were 13 women and 1 man with a mean age of 55 +/- 4 years (range 23 to 73). Mitral balloon valvuloplasty resulted in an increase in mitral valve area from 0.8 +/- 0.1 to 1.7 +/- 0.2 cm2 (p = 0.001), a decrease in mean mitral diastolic pressure gradient from 15 +/- 2 to 7 +/- 1 mm Hg (p = 0.001) and an increase in cardiac output from 3.4 +/- 0.3 to 3.9 +/- 0.3 liters/min (p = 0.03). No deaths, strokes, vascular complications or conduction abnormalities were observed. Mitral regurgitation developed or increased in severity in seven patients (50%). There was no evidence of significant left to right shunt through the atrial septal puncture site after mitral balloon valvuloplasty. A good result (defined as a mitral valve area greater than 1.0 cm2, an increase in mitral valve area greater than 25% and a mean gradient less than 10 mm Hg) was achieved in 9 (64%) of the 14 patients. A subgroup of four patients who had a superior result (increase in mitral valve area of 1.7 +/- 0.2 versus 0.5 +/- 0.1 cm2 in the other 10 patients, p = 0.004) was identified. These patients had less echocardiographic evidence of rheumatic mitral valve damage and were the only patients who had sinus rhythm. They were also younger, less debilitated and had a lower grade of fluoroscopic valve calcification compared with the other patients. Thus, mitral balloon valvuloplasty is a safe and effective procedure for patients with recurrent mitral stenosis after surgical commissurotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous mitral balloon valvotomy during pregnancy in a patient with severe mitral stenosis.

Percutaneous mitral balloon valvotomy (PMV) was performed successfully in a 41-year-old pregnant patient with severe mitral stenosis. The patient had a 21-week gestation and was severely limited by symptoms resulting from critical mitral stenosis. PMV resulted in a decrease in the diastolic mitral gradient from 26 to 2 mm Hg and an increase in both cardiac output (from 4.2 to 5.7 l/min) and mitral valve area (from 0.7 to 3.7 cm2). She had marked symptomatic improvement, no further heart failure, and a full-term, normal delivery. This case report indicates that PMV may be the treatment of choice in the management of pregnant patients with incapacitating symptoms caused by severe mitral stenosis.

Degree of reversibility of left ventricular systolic dysfunction after aortic valve replacement for isolated aortic valve stenosis.

To determine whether a low preoperative left ventricular (LV) ejection fraction (EF) returns to normal late after aortic valve replacement for aortic stenosis, 42 patients with critical aortic stenosis (valve area 0.7 cm2 or less), LV systolic dysfunction (EF 0.45 or less), angiographically normal coronary arteries, and no other significant valvular disease were studied at 10 to 84 months (mean 41 +/- 21) postoperatively. All patients survived aortic valve replacement and were discharged clinically improved. There were 4 late deaths; these patients were older (79 +/- 6 vs 64 +/- 13 years, p = 0.007) and had lower preoperative mean valve gradients (51 +/- 6 vs 68 +/- 23 mm Hg, p = 0.003) than late survivors. Of 23 survivors who returned for follow-up radionuclide angiography and Doppler echocardiography, 21 were asymptomatic. EF returned to normal (0.50 or more) in 14 patients (group 1) and remained low in 9 patients (group 2). Doppler peak prosthetic valve gradient was 24 +/- 8 mm Hg in group 1 and 25 +/- 10 mm Hg in group 2 (difference not significant). Six of the 9 patients in group 2 underwent early postoperative radionuclide imaging, and LVEF was normal in 4 (0.65 +/- 0.14 early vs 0.41 +/- 0.06 late, p = 0.02). Of 77 preoperative and intraoperative variables analyzed, only paroxysmal nocturnal dyspnea (0 of 14 vs 4 of 9, p = 0.01) distinguished group 1 from group 2. Thus, LVEF does not always normalize after aortic valve replacement for AS, implying impaired myocardial contractility.(ABSTRACT TRUNCATED AT 250 WORDS)