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Biomedical subjects

D A Murphy

Publications and source records attributed to D A Murphy.

At least 127 records · Page 7Linked to original sources
PubMed1984

Distal coronary artery dissection following percutaneous transluminal coronary angioplasty.

The most common cause of acute myocardial ischemia following percutaneous transluminal coronary angioplasty is coronary dissection, which characteristically remains localized to the site of balloon dilation. In this article, however, we report on 4 patients in whom percutaneous transluminal coronary angioplasty was complicated by coronary artery dissection extending distally beyond the site of anticipated vein graft anastomosis. Intraoperative diagnosis of distal coronary dissection is suggested by a characteristic appearance of the artery and confirmed by the finding of true and false lumens at the time of coronary arteriotomy. Successful revascularization is achieved by anastomosis of a vein graft to the true lumen with reapproximation of the dissected arterial layers. Proximal coronary artery ligation in this setting is unnecessary.

Adult↗
PubMed1984

Right atrial thromboemboli: clinical, echocardiographic and pathophysiologic manifestations.

In six patients with clinically unsuspected right atrial thromboemboli the diagnosis was made with two-dimensional echocardiography. Five patients had pulmonary emboli, and one had systemic embolization. Three patients had congestive cardiomyopathy, two with tricuspid regurgitation; of the remaining three, one had cor pulmonale complicated by tricuspid regurgitation, one had thrombophlebitis and one had no discernible cardiac illness. Four patients had dizziness or syncope, four had dyspnea, three had chest pain, three had hypotension and tow had cyanosis. Five patients were treated with thrombolytic or anticoagulant therapy, or a combination of the two. In three patients, surgical removal of the thrombus was undertaken because of recurrent pulmonary emboli or tricuspid regurgitation, or both, and progressive right heart failure. The thromboemboli were removed in all three, but one patient died. On two-dimensional echocardiography, four of the six patients' thromboemboli were snake-like, unattached to the right atrium and prolapsed freely across the tricuspid valve into the right ventricle in diastole and back into the right atrium in systole. The other two patients' thromboemboli were attached to the right atrium and did not prolapse across the tricuspid valve. Our cases, together with a review of other reports, suggest that right atrial thromboemboli: 1) can be accurately diagnosed by two-dimensional echocardiography; and 2) result from two different pathophysiologic mechanisms developing a) in situ, either on a foreign body or secondary to reduced cardiac output, or b) as a result of an embolus from systemic vein thromboses.

Adolescent↗
PubMed1984

Surgical management of acute myocardial ischemia following percutaneous transluminal coronary angioplasty. Role of the intra-aortic balloon pump.

Acute myocardial ischemia is a serious complication of percutaneous transluminal coronary angioplasty, often requiring emergency myocardial revascularization. Since our initial report of 17 such patients, we have encountered an additional 32 patients requiring emergency myocardial revascularization since September, 1981. The indication for emergency myocardial revascularization was ischemic chest pain in all 32 patients. Percutaneous transluminal coronary angioplasty resulted in injury to the right coronary artery in 11 patients, the left anterior descending artery in 19 patients, and the left main artery in two patients. The onset of ischemia was immediate in 26 patients but delayed up to 22 hours in six patients. Chest pain was associated with ST-segment elevation in 21 patients, hypotension in 7 patients, and cardiac arrest in 6 patients. Immediate intra-aortic balloon pumping was instituted in the angioplasty suite in 16 patients. The mean time from onset of ischemia to completed revascularization was 156 minutes with a mean of 1.6 grafts performed per patient. Seventeen patients (53%) had enzyme evidence of myocardial infarction postoperatively, with a significantly higher (p less than 0.01) incidence of myocardial infarction in those patients with preoperative ST elevation (76% versus 9%). In the 21 patients with ST-segment elevation, the incidence of Q wave infarction was 20% (3/15) with balloon pumping and 50% (3/6) without balloon pumping. Complications associated with intra-aortic balloon pumping occurred in one patient (6%). There were no hospital or late deaths with follow-up extending 16 months. The spectrum of injury resulting from percutaneous transluminal coronary angioplasty extends from chest pain alone to severe transmural ischemia with hypotension or cardiac arrest. Presentation may be immediate or delayed. Urgent emergency myocardial revascularization remains the accepted therapy for this complication. Immediate preoperative intra-aortic balloon pumping is a useful adjunct to emergency myocardial revascularization in the group of patients with acute ischemia and ST-segment elevation.

Acute Disease↗
PubMed1984

Combined carotid and coronary operations: when are they necessary?

Three groups of patients were analyzed to ascertain the risk of combined carotid/coronary operations and the risk factors for perioperative stroke following coronary artery bypass (CAB). Group 1 (N = 132) had simultaneous carotid endarterectomy and CAB, Group 2 (N = 51) were patients having perioperative stroke following elective CAB, and Group 3 (N = 169) had CAB alone but had prior history of either asymptomatic cervical bruit, stroke/transient cerebral ischemic attack (TIA), or carotid endarterectomy. Hospital mortality and perioperative stroke rate in the combined carotid/coronary group were 3.0% (4/132) and 1.6% (2/126), respectively. These rates were not significantly different from those of a control group having CAB alone. Overall incidence of postoperative stroke in 5,676 patients having CAB alone was 0.9% (51 patients). The incidence of perioperative stroke in patients with asymptomatic bruit or prior history of stroke or TIA undergoing CAB alone was 3.3% (2/60) and 8.6% (6/70), respectively. The majority of strokes following CAB appear to be embolic in origin. Indications for simultaneous carotid/coronary operations are bilateral carotid disease and symptomatic carotid vascular disease associated with unstable angina, left main obstruction, or diffuse multivessel disease. Staged procedures are recommended for patients with stable angina and symptomatic carotid lesions and for difficult carotid revascularization procedures. CAB alone may be performed for most patients with asymptomatic cervical bruit, moderate or mild carotid artery obstruction, and unstable angina associated with prior stroke, although in the third situation postoperative risk of neurological injury may be increased.

Aged↗
PubMed1984

Coronary revascularization in the presence of ascending aortic calcification: use of an internal mammary artery-saphenous vein composite graft.

Complications arising from manipulation of the diseased ascending aorta constitute a significant portion of the morbidity and mortality of coronary revascularization. A case is described in which coronary revascularization was achieved by extension of the left internal mammary artery with a segment of reversed saphenous vein. The major advantage of this technique is that it obviates any instrumentation of the aorta or great vessels.

Aged↗
PubMed1983

Effect of positive end-expiratory pressure on excessive mediastinal bleeding after cardiac operations. A controlled study.

The efficacy of mechanical ventilation with positive end-expiratory pressure (PEEP) in the therapy of excessive mediastinal hemorrhage following cardiac operations remains unproved. One hundred thirty-nine patients undergoing elective myocardial revascularization were divided into two groups on the basis of preoperative hematologic evaluation: Group I, 94 patients with no history of hematologic abnormalities and a normal coagulation profile; Group II, 45 patients with a recent use of antiplatelet medications and/or a prolonged template bleeding time. Both groups were randomized to receive mechanical ventilation with 10 cm H2O of PEEP or no PEEP beginning 1 hour after operation and continuing for an 8 hour study period. Mean blood loss at 8 hours (BVt) was not significantly different between PEEP and control patients in either group. Fifty-seven patients in Groups I and II had mediastinal bleeding in excess of 180 ml/hr at the initiation of the study period. There was no significant difference in mean BVt or mean hourly chest tube output with or without PEEP in either group of this subset. In view of the lack of demonstrable efficacy in decreasing mediastinal hemorrhage and the potential of adverse hemodynamic effects, PEEP should no longer be used for therapy of excessive bleeding after cardiac operation, especially in patients with reduced cardiac reserve.

Adult↗
PubMed1983

Mechanical valves: a comparative analysis of the Starr-Edwards and Björk-Shiley prostheses.

Despite the requirement of anticoagulation, mechanical valve prostheses offer the advantage of proven durability. We have compared the long-term results of 467 aortic valve replacements and 342 mitral valve replacements using the Starr-Edwards prosthesis with 110 aortic valve replacements and 105 mitral valve replacements using the Björk-Shiley prosthesis from 1973 through 1977. Improvement in New York Heart Association (NYHA) class was noted in greater than 80% of patients in all four groups. Long-term survival with mean follow-up over 5 years was not significantly different between respective groups. The probability of thromboembolic complications, however, was significantly higher (p less than 0.05) with the Starr-Edwards prosthesis in both the aortic and mitral positions. The probability of valve failure, although low for all groups, was significantly higher (p less than 0.05) in the Björk-Shiley mitral group due to late thrombotic occlusion. Use of the Starr-Edwards and Björk-Shiley prostheses is associated with satisfactory functional improvement and similar long-term survival rate. However, the increased risk of valve failure due to late thrombotic occlusion of the Björk-Shiley prosthesis should be considered when choosing a mechanical mitral prosthesis.

Actuarial Analysis↗
PubMed1983

Recognition and management of ascending aortic dissection complicating cardiac surgical operations.

This study retrospectively reviews the hospital records of 24 patients who developed ascending aortic dissection during or following 6,943 cardiac surgical procedures performed from January, 1971, through December, 1981. Group I consists of 15 patients with ascending aortic dissection presenting intraoperatively during myocardial revascularization. Group II consists of nine patients, seven who underwent myocardial revascularization and two who underwent aortic valve replacement, who developed ascending aortic dissection 30 minutes to 21 days after cardiac operation. Four of these patients had poorly controlled hypertension postoperatively. Surgical repair was attempted in all patients in Group I, with an operative mortality of 33%. The major cause of death was myocardial dysfunction secondary to ischemia. There were no operative deaths among six patients managed with closed plication techniques alone. Four of nine patients in Group II underwent ascending aortic dissection repair with an operative mortality of 50%. The overall mortality in Group II was 78%. The major factor in this high mortality was a delay in diagnosis and surgical therapy. Early diagnosis of the intraoperative or postoperative ascending aortic dissection process is essential to minimize the extent of dissection and prevent delay of definitive surgical therapy. Closed aortic plication of the intimal injury rather than more extensive aortic repair may reduce morbidity and mortality in selected patients.

Adult↗
PubMed1982

Isolation of single atrial and ventricular cells from the human heart.

The single isolated heart cell has recently emerged as a model for the study of the structure and function of cardiac cells. Heart muscle cells of adult animals of various species have been successfully isolated by enzymatic digestion of intact cardiac tissue. In this paper a dissociation method that yields living cells from atrial and ventricular tissue of young and adult humans is detailed. The cells retain the morphologic features of cells in intact cardiac tissue, and they generate action potentials and contractions in response to electrical stimulation. The study of isolated human heart cells should make a valuable contribution to knowledge of the normal and diseased heart.

Adult↗
PubMed1982

Concomitant carotid and coronary artery reconstruction.

Data are presented on 68 patients who underwent concomitant carotid endarterectomy (CE) and coronary artery bypass surgery (CAB) at Emory University Hospital from January 1974 to February 1981. This group is then compared with a randomly selected, matched population without known carotid disease who underwent CAB alone. Asymptomatic bruit was the reason for investigation in 40 patients (59%); another 23 patients (34%) experienced transient cerebral ischemic attacks (TIAs); and five patients (7%) had TIA and prior stroke. Carotid stenoses (>75% luminal narrowing) were demonstrated as follows: isolated left, 24 patients; isolated right, 27 patients; and bilateral lesions, 16 patients. One patient had innominate artery stenosis. Associated total occlusion of one or both vertebral arteries was demonstrated in six patients. Ninety-seven per cent of patients had disabling angina pectoris prior to operation; the angina was unstable in 57%, 15% had congestive heart failure, and 54% had had at least one prior myocardial infarction (MI). Single-vessel coronary disease was present in 12.5% of patients, double in 37.5%, triple in 41.1%, and left main stenosis in 9%; 43% of patients had abnormal ventricular contractility. CE was performed on 67 patients (36 left and 31 right); aortocarotid bypass was performed on one. The CE procedures were performed immediately prior to the sternotomy for CAB under the same anesthesia. CAB consisted of single bypass in eight patients (11.8%); double in 16 patients (23.5%); triple in 22 patients (32.4%); and quadruple or more in 22 patients (32.4%) (mean = 2.9 grafts per patient). There was no hospital mortality. Perioperative MI occurred in 2.0% and stroke with residual deficit in 1.3%. Cumulative survival is 98.5% at two years. Sixty-three patients (92%) reported improvement or elimination of anginal symptoms after operation. Rehospitalization for stroke was necessary in 3.7% patients. Postoperative activity levels are; self-care only, 3.9%; normal daily activity only, 17.6%; moderate exercise capability, 45%; and vigorous exercise capability, 33%. Comparison was made with a group of 84 randomly selected patients who underwent CAB alone during the same time interval. Data revealed no significant difference between the groups regarding sex, angina subset, ventricular function, coronary anatomy, vessels grafted, perioperative stroke or MI, mortality, or postoperative activity capability. Older age (59.8 vs. 55.6, p < 0.01) and less complete coronary revascularization possible (66 vs. 84%, p < 0.05) in the CECAB group were the only significant differences. Carotid stenosis co-existing in patients requiring CAB should be concomitantly corrected with the same risk and results expected from CAB alone.

Aged↗
PubMed1982

Surgical revascularization following unsuccessful percutaneous transluminal coronary angioplasty.

From September, 1980, through August, 1981, 353 patients underwent attempted percutaneous transluminal coronary angioplasty (PTCA). Twenty-seven patients (7.6%) subsequently underwent elective myocardial revascularization without death or complicating PTCA. Surgical support in the first 2 months involved a fully-staffed operating room standing idle. During the last 10 months, patients requiring emergency revascularization were accommodated in the first operating room available. All 17 patients undergoing emergency revascularization had severe chest pain and 12 patients had ST-segment elevation on the electrocardiogram. The average time from onset of ischemia to revascularization was 135 minutes and did not change over the period of study. Improvement in the electrocardiogram and myocardial function were frequently noted with restoration of flow by the vein graft. Two patients (12%) required inotropic drug support following revascularization. All 12 patients with ST-segment elevation preoperatively had elevated myocardial enzyme levels postoperatively, including five patients (29%) with new Q waves on the electrocardiogram. Myocardial necrosis did not correlate with time to revascularization, number of diseased vessels, the artery being instrumented, the mechanism of ischemia, or the presence of collateral flow. There were no deaths. Because of the high incidence of myocardial infarction despite prompt revascularization, we now routinely insert the intra-aortic balloon pump in the catheterization laboratory in patients with refractory myocardial ischemia requiring emergency revascularization. Prompt safe revascularization for acute ischemia following PTCA can be achieved without expensive and inefficient standby of cardiac surgical facilities. Transmural myocardial ischemia following complicated PTCA is frequently associated with evidence of myocardial necrosis despite prompt surgical revascularization. Greater salvage of ischemic myocardium may be possible if the intra-aortic balloon pump is used in the interval between PTCA-induced injury and surgical revascularization.

Adult↗
PubMed1982

Polytetrafluoroethylene shunts in congenital heart disease.

Over a 2-year period the authors inserted 22 systemic to pulmonary artery shunts using a polytetrafluoroethylene (PTFE) graft in 19 children. A modified Blalock-Taussig shunt was established in 18 instances and an aorta to pulmonary artery shunt in 3: one patient had an aorta to right ventricle infundibulum shunt. Three children had obstructed grafts and in two others the grafts became stenosed; on of the latter group had successful removal of thrombus. The remaining grafts functioned well. Three other patients are presented. In two an interrupted aortic arch was repaired using a PTFE graft; one of these patients died at later closure of an aortopulmonary window, the other did well following repair of a ventricular septal defect and aortic valvotomy. The third child had a right ventricle to pulmonary artery shunt established for tetralogy of Fallot with pulmonary atresia; this resulted in some growth of the pulmonary arteries. The modified Blalock-Taussig shunt, using a PTFE graft, can be inserted without opening the pericardium, normal flow through the subclavian artery is not interrupted, the PTFE is easy to handle and the shunt can be inserted and taken down more easily than traditional shunts. For these reasons, the authors believe that this procedure, using PTFE, has an important role to play in the surgical management of children with congenital heart disease.

Aorta, Thoracic↗
PubMed1981

Intraventricular repair of double-outlet left ventricle.

A 3 1/2-year-old child with double-outlet left ventricle and subaortic ventricular septal defect underwent successful surgical intervention with an intraventricular repair and a boomerang-shaped piece of Dacron patch. While an intraventricular repair for double-outlet left ventricle has been reported, we discuss here its application to this particular type of double-outlet left ventricle.

Angiography↗
PubMed1981

Polymicrobial purulent pericarditis.

A 63-year-old man had polymicrobial purulent pericarditis secondary to a silent esophageal perforation into the pericardium. His hospital course was complicated and prolonged. Defunctioning of his esophagus was needed to cure his pericarditis. The authors recommend an aggressive approach to his rare condition, emphasizing the importance of early defunctioning of the esophagus.

Bacterial Infections↗
PubMed1980

Suppression of renin production in patients undergoing coronary artery bypass.

Twenty patients undergoing elective myocardial revascularization for coronary insufficiency were divided into two equal groups. In 10 patients, propranolol was discontinued 24 hours before operation while the remaining patients received propranolol until the day of operation. Plasma renin was elevated in the intensive care unit in the control group (p < 0.05) whereas patients receiving propranolol did not demonstrate significant elevation of plasma renin. Systemic vascular resistance was elevated in both groups in the intensive care unit (p < 0.05) and was associated with hypertension as defined by a blood pressure of greater than or equal to 160/100 mm Hg in 80% of the control patients and 70% of patients receiving propranolol. We conclude from this study that renin metabolism does not contribute significantly to the production of hypertension following coronary artery operation.

Adult↗