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Biomedical subjects

J R Pluth

Publications and source records attributed to J R Pluth.

At least 19 recordsLinked to original sources

Surgical treatment of ascending aortic aneurysms associated with aortic valve insufficiency.

From 1965 to 1978, 111 patients underwent combined operation for ascending aortic aneurysms and aortic valve insufficiency. Fifteen patients had direct coronary implantation (Group 1). In 25 patients operated on between 1972 and 1977, the aortic root was retained (Group 2). An additional 71 patients operated on between 1965 and 1972 were included (Group 3): 40 who had synthetic graft replacement and retention of the aortic root and 31 who had aortoplasty and associated aortic valve repair. In 8 patients in Group 3, recurrent aneurysms were detected an average of 6.5 years after operation. The mortality rate for repaiajor complication after incomplete resection of the aortic root. Total exclusion of the aneurysm should be considered.

Adolescent

Modified continuous suture technique for mitral valve replacement.

A modified continuous suture technique for mitral valve replacement is described which retains desirable features of the less expedient interrupted suture technique. An initial experience with this technique in more than 300 patients has encouraged its continued use.

Heart Valve Prosthesis

Efficacy of dopamine, dobutamine, and epinephrine during emergence from cardiopulmonary bypass in man.

Hemodynamic effects of dobutamine and dopamine (both 5, 10, 15 microgram/kg/min) and epinephrine (0.04 microgram/kg/min) were studied immediately following cessation of cardiopulmonary bypass in 34 patients with preoperative evidence of left ventricular dysfunction. Significant increases in mean cardiac index were seen with dobutamine (15, 25, and 26% respectively), and epinephrine (30%). The largest increases occurred with dopamine (44, 53, and 64 percent respectively). Responses varied from patient to patient, however. Seven patients developed marked output increases without concomitant increases in arterial pressure, whereas seven others showed "satisfying" increases in arterial pressure without appreciable output increases. Heart rate increases were small and few arrhythmias were noted. We conclude that dopamine, epinephrine, and dobutamine all are effective inotropic agents during the immediate post-bypass period, with variations discussed in detail. None possess the disturbing chronotropic and arrhythmogenic effects of isoproterenol (previously studied). Efficacy of administration of inotropic drugs seems best assessed by serial output measurements during this period.

Arrhythmias, Cardiac

Regional myocardial wall thickening response to nitroglycerin. A predictor of myocardial response to aortocoronary bypass surgery.

The peak rate of systolic wall thickening (p +/- dTw/dt) in regions of the left ventricle (LV) was determined preoperatively by biplane roentgen videometry in 18 patients before and after sublingual administration of nitroglycerin (NTG) and 3-23 months (median 12) after aortocoronary bypass surgery. The regional LV response to NTG was a reliable predictor for postoperative improvement in regional wall dynamics after successful aortocoronary bypass grafting. The ejection fraction response to NTG or surgery will not predict the regional myocardial response to NTG or surgery, nor will the regional response predict the global response. Subendocardial myocardial infarction is another cause of unimproved regional myocardial function after NTG and aortocoronary bypass surgery.

Adult

Platelet imaging.

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Arteriosclerosis

Perioperative myocardial infarction in patients with coronary artery disease with and without aorta--coronary artery bypass grafts.

The incidence of perioperative myocardial infarction (MI) was examined in 148 patients with known coronary artery disease (CAD) who underwent 226 noncardiac surgical procedures. In 168 operations in 99 patients who had prior coronary artery bypass grafting (CABG) there were no perioperative MI's whereas in the 49 patients who had not undergone prior CABG who underwent 58 noncardiac operations, there were three MI's (5 percent). The lower (p less than 0.02) incidence of perioperative MI in patients with CAD who had had prior CABG suggests a protective effect for subsequent noncardiac operation, which could not be explained by other differences in cardiac status between the groups. All three MI's occurred in patients with three-vessel CAD, evidence that this should be added to prior MI as a significant risk factor. The study indicates also that patients with prior CABG have less risk of MI during and following anesthesia and noncardiac operation than do patients without CABG who have had a previous MI.

Adult

The Marfan syndrome and cardiac surgery.

Of 31 patients with Marfan's syndrome and cardiovascular complications, 25 had ascending aortic aneurysms, five with aortic dissection; 26 had aortic regurgitation, two with aortic stenosis; and eight had mitral regurgitation, five with aortic regurgitation. Surgery included prosthetic aortic valve replacement in 24 patients and aortic valvular bicuspidization in two; 19 had resection of aneurysm with Dacron tube replacement, three had lateral aneurysmorrhaphy, and two had circumferential strip excision with end-to-end anastomosis. Four patients underwent mitral valve replacement. Operative complications occurred in 10 patients. There were nine (29 percent) hospital deaths, but only one death occurred in 12 patients operated upon since 1970. Late complications included prosthetic leak in six patients (23 percent) with reoperation in five; all survived. Five late deaths occurred (16 percent); one was unrelated and one was of unknown cause. Although risk of cardiac surgery remains high, our recent results support an aggressive surgical approach, particularly in patients with advanced or deteriorating cardiovascular complications.

Adolescent

Partial anomalous pulmonary venous connection (intact atrial septum) associated with mitral regurgitation.

The association of partial anomalous pulmonary venous connection with intact atrial septum and isolated severe nonrheumatic mitral regurgitation is rare, this combination of lesions having been reported on only one other occasion. Two such cases have been presented, with each patient having experienced an episode resembling subacute bacterial endocarditis. At operation, however, the mitral valve had a congenital cleft in one case and was normal in the other. One patient underwent mitral valvuloplasty and the second patient had mitral valve replacement. The diagnosis of associated partial anaomalous pulmonary venous connection was established at cardiac catheterization, and successful surgical correction was achieved in each case by diversion of the anamolaous pulmonary venous drainage to the left atrium via a pericardial tunnel through a surgically created atrial septal defect.

Adult

The performance of the Braunwald-Cutter aortic prosthetic valve.

Four hundred seventy-five patients underwent aortic valve replacement with the Braunwald-Cutter ball-valve prosthesis at two institutions. The early (30-day) hospital mortality was 4.7% for those with isolated aortic valve replacement and 6.9% for the entire group. For the former, 5-year actuarial survival of the hospital survivors was 72 +/- 5.7%; for the latter group it was 71 +/- 4.4%. Eleven patients (5 since the date of follow-up inquiry) have suffered poppet escape, 9 of whom died. The actuarial incidence of known poppet escape is 4 +/- 2.6% at 47 months; when the 5 patients suffering poppet escape since the date of follow-up inquiry are included, with certain assumptions, the incidence is 3.7 +/- 1.14%. The projected probability of poppet escape using all 11 patients is 12.2% at 5 years; the 70% confidence bands of projected probability of poppet escape separate from those of the risk of re-replacement at 61 months. This and other analyses indicate that in general, patients with the Braunwald-Cutter aortic prosthesis should have it replaced 4 1/2 to 5 years after its insertion.

Alabama

A critical look at temporary ventricular pacing following cardiac surgery.

The effect of atrial, ventricular, and atrioventricular (A-V) sequential pacing on cardiac output (CO) was evaluated in patients within 24 hours after cardiac surgery. In patients with normal sinus rhythm, ventricular pacing reduced CO by as much as 42% (average, 14%), whereas atrial and A-V sequential pacing at the same rate increased CO by averages of 13% and 19%, respectively. In patients with junctional rhythm, increase of the heart rate by ventricular pacing produced an increase in CO, however, and an additional 25% increase in CO could be obtained by atrial or A-V sequential pacing at the same rate. Atrial or A-V sequential pacing was superior to ventricular pacing at the same rate and they are the preferred methods for temporary carciac pacing in the postoperative period. In suitable cases elective A-V sequential pacing is an effective method for increasing CO after cardiac surgery.

Adult

Survival predictors in coronary artery disease. Medical and surgical comparisons.

Linear discriminant function analysis was used to test the independent prognostic value of nine variables in patients with coronary artery diseaase. For 68 medically treated patients who met the criteria for inclusion in the discriminant function analysis, the most reliable predictor of 2-year survival status was the left ventricular ejection fraction. The prognostic value of the ejection fraction was not improved by the addition of the number of vessels diseased. Comparisons of the survival of 130 medical and 284 surgical patients were made using subsets based on the ejection fraction. When the ejection fraction was greater than or equal to 50%, the probability of 4-year survival was high for both medical (91%) and surgical (96%) groups. When the ejection fraction was less than 25%, the probability of 2-year survival was low in both groups. However, for patients with ejection fraction 25 through 49%, the surgical patients had a better chance (P less than 0.05) for a 3-year survival (89%) than did medical patients (68%). This study emphasizes the prognostic significance of the left ventricular ejection fraction, which should be considered in any comparison of survival in medically and surgically treated patients.

Age Factors

Intra-aortic balloon assist: initial Mayo Clinic experience and current concepts.

The initial experience with intra-aortic balloon assist (IABA) at the Mayo Clinic has been with 34 desperately ill individuals; 17 survived hospitalization. Hemodynamic improvement associated with institution of IABA can be documented. An unacceptably high complication rate (26%) has resulted in extensive modification in the technique of employing IABA. Concepts of patient selection and applications of IABA have evolved from this initial experience and from a review of the literature and have resulted in less reluctant use of this cardiac-assist modality.

Adult

Constrictive pericarditis.

A patient with constrictive pericarditis following an open-heart operation without sepsis is discussed. In the absence of sepsis, it has been widely held that this complication does not develop following an open-heart procedure. The fatal outcome in this patient could have been avoided had such an association been known.

Aortic Valve

Dobutamine for inotropic support during emergence from cardiopulmonary bypass.

Dobutamine, a recently introduced derivative of dopamine, is reported to retain inotropic properties with less pronounced chronotropic and arrhythmogenic effects than isoproterenol. The drug was evaluated in two doses, 5 mug/kg/min and 10 mug/kg/min, in two groups of ten patients each, during emergence from cardiopulmonary bypass. A third group of five patients was studied similarly with isoproterenol, 0.02 mug/kg/min. Cardiac index increased 16 and 28 per cent eith the two doses of dobutamine, respectively, and 9 per cent with isoproterenol. Heart rate, in contrast, increased 6 and 15 per cent with dobutamine (not significant) and 44 per cent with isoproterenol (significant). Dobutamine seemed to associated with fewer arrhythmias than isoproterenol. It is concluded that dobutamine, 5-10 mug/kg/min, is suitable for use during emergence from cardiopulmonary bypass and may possess advantages over isoproterenol.

Adult

Videometric analysis of regional left ventricular function before and after aortocoronary artery bypass surgery: correlation of peak rate of myocardial wall thickening with late postoperative graft flows.

The peak rate of systolic wall thickening (pdTw/dt) in regions of the left ventricle was determined by biplane roentgen videometry in 60 patients before and a median of 14 mo after aorto-coronary bypass graft surgery. The left ventricular ejection fraction, stroke volume, and end-diastolic volume and pressure did not change significantly after surgery in the presence of patent or occluded grafts (P greater than 0.05). Statistically significant increases occurred in the peak rate of systolic wall thickening regions supplied by patent bypass grafts, and significant decreases occurred in regions with occluded grafts (P less than 0.01). Of 42 preoperatively hypokinetic regions (pdTw/dt greater than 0 less than 5.0 cm/s) supplied by a patent graft, 30 improved by an average of 2.6 cm/s after operation; 18 returned to normal. Failure of 24 hypokinetic regions to improve to normal was associated with myocardial infarction in 11 or with late postoperative graft blood flows of less than 60 ml/min measured by videodensitometry, in 10. All seven preoperatively akinetic (pdTw/dt=0) or dyskinetic (pdTw/dt less than 0) regions did not improve after the operation despite the fact that, in five of the seven, coronary bypass flows were over 60 ml/min. All eight preoperatively hypokinetic regions supplied by coronary artery graft flows of less than or equal 40 ml/min failed to improve to normal after operation. All nine preoperatively hypokinetic regions supplied by coronary artery graft flows of over 60 ml/min improved to normal after surgery. Late postoperative coronary artery bypass graft flows, the functional status of the myocardium, the status and distribution of the native coronary circulation, and decreased regional function elsewhere in the ventricle must all be considered when regional left ventricular function is interpreted.

Adult