Search PubMed⌕ Search

Biomedical subjects

H DeMots

Publications and source records attributed to H DeMots.

At least 19 recordsLinked to original sources
PubMed1989

Intermittent transdermal nitroglycerin therapy in the treatment of chronic stable angina.

The effectiveness of an intermittent regimen of transdermal nitroglycerin in chronic stable angina was evaluated in 206 patients using serial treadmill testing. After a placebo stabilization phase, patients were randomized to 4 weeks of double-blind treatment with transdermal nitroglycerin, 10 or 20 cm2 (equivalent to 5 or 10 mg/24 h) (Group A); transdermal nitroglycerin, 30 or 40 cm2 (equivalent to 15 or 20 mg/24 h) (Group B), or placebo. Patches were applied at 8:00 AM and removed at 8:00 PM each day throughout the study. Treadmill testing was performed 0, 4, 8 and 12 h after patch application at baseline (day 0) and on days 1, 15 and 29. After short-term application of the transdermal patches, treadmill walking time was greater for patients in both Group A and Group B than for the placebo group at all time points tested; differences from placebo were statistically significant at 12 h for Group A and at 4, 8 and 12 h for Group B. After 2 and 4 weeks of long-term therapy, treadmill walking time was again greater for Group B than for the placebo group at all postapplication time points; differences from placebo reached statistical significance at 4 h (2 weeks) and 8 h (2 and 4 weeks). The improvement in the treadmill walking time seen over the short-term in Group A was largely lost after 4 weeks of long-term therapy. Potentially important differences in the patient characteristics of the two active treatment groups, particularly the greater use of a beta-adrenergic blocker among patients in Group A, may have contributed to these observed differences in treatment effect. An unexpected finding was the ability of the placebo group to exercise longer than either active treatment group just before patch application during long-term therapy; nonetheless, absolute responsiveness to transdermal nitroglycerin after patch application remained virtually unchanged in both active treatment groups during the 4 week treatment period. Intermittent transdermal nitroglycerin therapy was well tolerated in the vast majority of patients; nine patients experienced an increase in nonexertional angina during the patch-off periods but completed the study uneventfully.

Administration, Cutaneous↗
PubMed1987

Coronary arteriography performed by a physician assistant.

Funding constraints and an oversupply of cardiologists mitigate against continued training of increasing numbers of cardiology fellows. In some institutions, the workload of the catheterization laboratory is an overriding factor. The ability of a physician assistant to perform some of this work was tested to determine if the number of fellows and the content of the fellowship training program could be uncoupled from the catheterization laboratory workload. Among the first 150 patients in whom coronary arteriography was performed by a physician assistant, no patient died or had a myocardial infarction or stroke. Two patients (1.3%) had minor complications: a retinal embolus and an infected puncture site. The complication rate in 150 consecutive cases performed by fellows was also 1.3%, a small myocardial infarction and a transient ischemic attack. Procedure times for the physician assistant and for the fellows were 41 +/- 13 and 44 +/- 18 minutes for preoperative patients and 62 +/- 24 and 70 +/- 20 minutes for postoperative patients. Corresponding fluoroscopy times were 11 +/- 5 and 12 +/- 7 minutes for the preoperative and 22 +/- 12 and 20 +/- 6 for postoperative patients. Only preoperative fluoroscopy times were statistically different (p = 0.02). Thus, substituting a physician assistant for a fellow to perform coronary arteriography is an option in institutions at which the number of studies exceeds the training needs of fellows.

Angiography↗
PubMed1983

Protective effects of aspirin against acute myocardial infarction and death in men with unstable angina. Results of a Veterans Administration Cooperative Study.

We conducted a multicenter, double-blind, placebo-controlled randomized trial of aspirin treatment (324 mg in buffered solution daily) for 12 weeks in 1266 men with unstable angina (625 taking aspirin and 641 placebo). The principal end points were death and acute myocardial infarction diagnosed by the presence of creatine kinase MB or pathologic Q-wave changes on electrocardiograms. The incidence of death or acute myocardial infarction was 51 per cent lower in the aspirin group than in the placebo group: 31 patients (5.0 per cent) as compared with 65 (10.1 per cent); P = 0.0005. Nonfatal acute myocardial infarction was 51 per cent lower in the aspirin group: 21 patients (3.4 per cent) as compared with 44 (6.9 per cent); P = 0.005. The reduction in mortality in the aspirin group was also 51 per cent--10 patients (1.6 per cent) as compared with 21 (3.3 per cent)--although it was not statistically significant; P = 0.054. There was no difference in gastrointestinal symptoms or evidence of blood loss between the treatment and control groups. Our data show that aspirin has a protective effect against acute myocardial infarction in men with unstable angina, and they suggest a similar effect on mortality.

Adrenergic beta-Antagonists↗
PubMed1982

Natural history of "high-risk" bundle-branch block: final report of a prospective study.

We conducted a prospective study in which 554 patients with chronic bifascicular and trifascicular conduction abnormalities were followed for an average of 42.4 +/- 8.5 months. Heart block occurred in 19 patients, and 17 were successfully treated. The actuarial five-year mortality from an event that could conceivably have been a bradyarrhythmia was 6 per cent (35 per cent from all causes). Of the 160 deaths 67 (42 per cent) were sudden; most of these were not ascribable to bradyarrhythmia but to tachyarrhythmia and myocardial infarction. Mortality was higher in patients with coronary-artery disease (P less than 0.01) and congestive heart failure (P less than 0.05). Patients in whom syncope developed before or after entry into the study had a 17 per cent incidence of heart block (2 per cent in those without syncope)(P less than 0.05); however, no single variable was predictive of which patients were at high risk of death from a bradyarrhythmia. The predictors of death were increasing age, congestive heart failure, and coronary-artery disease; the predictors of sudden death were coronary-artery disease and increasing age. The risks of heart block and of death from a bradyarrhythmia are low; in most patients, heart block can be recognized and successfully treated with a pacemaker.

Aged↗
PubMed1981

Preoperative criteria predictive of late survival following valve replacement for severe aortic regurgitation.

Forty-five patients underwent aortic valve replacement (AVR) for severe isolated aortic regurgitation from 1973 to 1979. There were two (4.4%) hospital deaths, both functional class IV. Six patients with mechanical prosthesis not receiving anticoagulants were excluded from further analysis. These data relate to 39 patients; the two operative deaths, 35 patients with mechanical prosthesis receiving anticoagulants, and two with bioprosthesis. There were three late cardiac deaths with 5-year survival 85%; average annual mortality rate of 3%. The 5-year survival with pre-AVR left ventricular (LV) ejection fraction greater than or equal to 0.45 was 87% vs 54% less than 0.45, (p less than 0.04); cardiac index greater than or equal to 2.5 L/min/m2 92% vs 66% less than 2.5 (p less than 0.04); mean VCF greater than or equal to 0.75 vs less than 0.75 circ/sec (p less than 0.09); end-diastolic pressure less than or equal to 20 vs greater than 20 mm Hg (p less than 0.08). Late survival was not significantly different between pre-AVR functional class I and II vs class III and IV; LV end-diastolic volume index greater than or equal to 210 vs less than 210 ml/m2; LV end-systolic volume index greater than or equal to 110 vs less than 110 ml/m2; and LV mass greater than or equal to 240 vs less than 240 gm/m2. With ejection fraction greater than or equal to 0.50 there was only one operative death (functional class IV) and no late cardiac deaths. Thus late survival following aortic valve replacement for severe isolated aortic regurgitation is better predicted preoperatively by the LV systolic pump function variables of ejection fraction and cardiac index than by LV diastolic parameters and clinical status.

Adolescent↗
PubMed1981

Mechanism for improved cardiac performance with arteriolar dilators in aortic insufficiency.

To determine how arteriolar dilation improves cardiac performance in aortic insufficiency, we evaluated the acute effects of hydralazine in 10 patients with chronic severe aortic insufficiency. Control measurements of intracardiac and intravascular pressures, cardiac output and left ventricular volumes were obtained at cardiac catheterization. Hydralazine, 0.3 mg/kg i.v. (maximal dose 20 mg), was administered and all measurements were repeated 30 minutes later. A reduction in systemic vascular resistance from 1264 to 710 dyn-sec-cm-5 was associated with significant increases in forward cardiac index (2.9 to 5.1 l/min/m2) and stroke volume index (37 to 55 ml/m2). Left ventricular end-diastolic pressure was reduced from 19 to 12 mm Hg. There was a significant reduction in mean arterial pressure (88 to 83 mm Hg) and a significant increase in heart rate (81 to 94 beats/min). Regurgitant stroke volume was reduced by more than 10 ml/m2 in seven patients and for the group was significantly reduced, from 65 to 53 ml/m2. Regurgitant fraction was reduced in all patients; the overall reduction from 0.64 to 0.48 was highly significant. Ejection fraction increased more than 0.10 in four patients, by 0.08 in an additional patient and for the group increased significantly from 0.50 to 0.57. Left ventricular end-diastolic volume decreased by more than 25 ml/m2 in four patients, by 19 ml/m2 in an additional patient and was decreased significantly, from 208 to 190 ml/m2, for the group. Arteriolar dilators improve cardiac performance in aortic insufficiency by reducing the amount of aortic regurgitation and, in some patients, by substantially improving systolic pump fraction. These data suggest a role for arteriolar dilators in the management of selected patients with aortic insufficiency.

Adult↗
PubMed1980

Beneficial effects of hydralazine on rest and exercise hemodynamics in patients with chronic severe aortic insufficiency.

We studied the effects of afterload reduction in chronic severe aortic insufficiency by measuring the hemodynamic response to oral hydralazine in 10 consecutive patients. Hemodynamics were also measured during maximal exercise in eight of these patients. At rest, hydralazine reduced pulmonary artery wedge pressure from 14 to 9 mm Hg (p less than 0.01), and increased cardiac index by 70% and stroke volume index by 35% (both p less than 0.001). Before hydralazine, pulmonary artery wedge pressure exceeded 20 mm Hg in five patients during maximal exercise; with hydralazine, at identical levels of exercise, pulmonary artery wedge pressure remained below 20 mm Hg in all patients. For the group, hydralazine reduced pulmonary artery wedge pressure from 21 to 12 mm Hg (p less than 0.05) and increased cardiac index by 31% (p less than 0.05) during exercise; changes in stroke volume index were more variable and there was no significant increase for the group, although several patients increased stroke volume substantially and the overall increase was 34%. These data show that afterload reduction has beneficial effects on cardiac performance in chronic severe aortic insufficiency both at rest and during exercise. Hydralazine may be of use in such patients either in preparation for valve replacement or as interim therapy.

Adult↗
PubMed1979

Failure of antiplatelet and anticoagulant therapy to improve patency of grafts after coronary-artery bypass: a controlled, randomized study.

Fifty patients who underwent aortocoronary saphenous-vein bypass-graft surgery were randomly assigned to one of three groups to determine the effects of antiplatelet or anticoagulant therapy on graft patency. Twenty-four patients served as controls; 13 patients received aspirin (325 mg three times a day) and dipyridamole (75 mg three times a day); and 13 patients received closely regulated warfarin therapy. Medications were begun on the third post-operative day. Six months after surgery, all patients underwent coronary angiography to assess graft patency. There were no statistically significant differences between groups in various clinical, hemodynamic and angios, 27 of 33 grafts (82 per cent) with aspirin and dipyridamole and 29 of 37 grafts (78 per cent) with warfarin (P less than 0.5), all patients had at least one patent graft. Postoperative treatment either with aspirin and dipyridamole or with warfarin failed to improve the patency of the grafts.

Aged↗
PubMed1979

Spontaneous return of patency in a completely occluded coronary artery.

We observed a 56-year=old man in whom an occluded right coronary artery was observed to be widely patent on a subsequent angiogram 40 months later. This "regression," which occurred without a change in his risk factors, shows that manipulation of risk factors can be proven to be a cause of regression only in controlled studies.

Coronary Angiography↗
PubMed1978

A prospective study of sudden death in "high-risk" bundle-branch block.

We prospectively followed 257 patients with bifascicular and trifascicular conduction-system disease and intact atrioventricular conduction who had undergone His-bundle studies. Forty-seven per cent had associated coronary-artery disease, and 23 per cent primary conduction-system disease. His-ventricular interval was moderately prolonged in 43 per cent and markedly prolonged in 12 per cent. During an average follow-up period of 25 months 50 patients died. However, death was sudden in only 27, and 17 of the sudden deaths were not due to bradyarrhythias. Actuarial analysis showed an overall mortality rate (mean +/- S.E.) of 19 +/- 2.6 per cent at two years, mortality from sudden death being 10 +/- 2.6 per cent. Permanent heart block occurred in 12. No clinical symptoms (including syncope), electrocardiographic findings, electrophysiologic data or their combination identified patients at high risk of sudden death. Sudden death due to bradyarrhythmia is uncommon in patients with bundle-branch block and intact atrioventricular conduction. Therefore, routine prophylactic use of permanent pacemakers in all such patients is inappropriate. Pacemaker implantation should be reserved for those with documented symptomatic bradyarrhythmias.

Adult↗
PubMed1978

Diastolic rumbles with porcine heterograft prosthesis in the atrioventricular position. Normal or abnormal prosthesis?

Three patients with porcine atrioventricular valves (two mitral, one tricuspid) with diastolic rumbles and presystolic murmurs are presented. Full hemodynamic and angiographic studies demonstrated moderate to severe prosthetic stenosis, even in the one patient who was minimally symptomatic. Diastolic murmurs across atrioventricular porcine heterografts indicate prosthetic stenosis until proved otherwise by full hemodynamic and angiographic studies. If the studies indicate normal function of the device and calculated prosthetic valve area that is small for the patient, then it must be recognized that the device is hemodynamically "stenotic" for that particular patient (valve prosthesis--patient mismatch).

Adult↗