摘要:

Despite the development of trained mobile rescue squads, cardiopulmonary collapse outside the hospital continues to carry a poor prognosis. We examined retrospectively the clinical courses of 19 consecutive coronary unit patients who had experienced prehospital cardiopulmonary resuscitation. Seven patients received basic life support from bystanders within five minutes. Cardiopulmonary resuscitatiorn in the other 12 patients was delayed beyond five minutes pending the arrival of rescue personnel. Six of seven early-resuscitated patients survived compared with six of 12 late-resuscitated patients (P < 0.01). The early-resuscitated patients were more alert on admission and had lower pulmonary pressures and higher cardiac outputs compared to the late-resuscitated patients. The early-resuscitated patients also had less residual central nervous system and myocardial damage on discharge than the lateresuscitated patients. On follow-up, three early-resuscitated patients had returned to full-time work compared with none in the late group. Training laymen to initiate early basic life support can benefit the cardiopulmonary collapse victim.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Myocardial infarction after coronary artery bypass graft (CABG) surgery has been described clinically in up to 30%percnt; of patients but there is little morphologic information about the character and pathogenesis of this myocardial injury. We studied myocardium in the distribution of bypassed and nonbypassed coronary arteries for the presence of contraction band necrosis as compared to coagulation necrosis, in 58 autopsied patients who died less than 1 month after surgery. Operation related necrosis consisting of focal subendocardial contraction band necrosis was present to some degree in 48 (83%percnt;) patients. Regional transmural necrosis was present in 22 (38%percnt;) patients and was of two types. Contraction band necrosis occurred in 18 patients and was in the distribution of a patent bypassed coronary artery in 15 of them. Coagulation necrosis was found in four patients, and in each was in the distribution of a new graft-related coronary artery occlusion.The results suggest that coronary artery reflow through widely patent grafts following the period of operative nonperfusion, rather than graft or intrinsic coronary artery occlusion, accounts for the majority of operation-related myocardial “infarcts" associated with CABG surgery. Thus, prevention of intraoperative myocardial injury must also focus on characteristics of the phase of myocardial reperfusion.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The purpose of this study was to conduct a controlled evaluation of the continuous-wave Doppler technique for the estimation of stroke volume changes.Six anesthetized dogs were studied. Aortic blood velocity was recorded from the suprasternal notch by a special continuous-wave Doppler unit. Cardia output was varied by fluid infusion and exsanguination, and over 300 simultaneous records of aortic blood velocity and thermodilution cardiac output were taken. Average stroke volume and average systolic velocity integral (SVI), the area under the Doppler velocity curve, were calculated.The relationship of SVI to stroke volume was evaluated for each animal using linear regression. Average results were: correlation coefficient 0.95 ± 0.04 SD; y-intercept 0.38 ± 0.14 cm (SD); standard error of fit 0.29 ± 0.03 cm (SD).These data show that the systolic integral of aortic blood velocity was essentially directly proportional to stroke volume, even over a six-fold range. Thus, this technique will provide an accurate noninvasive estimate of changes in stroke volume.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The acute hemodynamic effects of dobutamine and nitroprusside were compared in 19 patients with low output cardiac failure. At dosage levels yielding similar increases in cardiac index (12 patients), nitroprusside resulted in significantly lower arterial systolic and wedge pressures and did not increase heart rate suggesting advantages over dobutamine when reduction in myocardial oxygen requirement or pulmonary congestion is a major goal. Systemic arterial mean and diastolic pressures were minimally changed with dobutamine, but fell significantly with nitroprusside suggesting advantages of dobutamine over nitroprusside in patients where hypotension could limit coronary blood flow or perfusion of other vital organs. Reduction in pulmonary arteriolar resistance occurred only with nitroprusside. Arterial hypoxemia developed in three patients during nitroprusside infusion suggesting the possibility of increased right-to-left intrapulmonary shunting resulting from a direct vasodilating effect of nitroprusside on pulmonary arteriole smooth muscle. Although both inotropic and vasodilator drugs can result in hemodynamic improvement when administered to patients with chronic low output cardiac failure, significant differences of potential clinical importance exist between these two modes of therapy.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Significant pericardial disease can exist without overt manifestations. Occult constrictive pericardial disease (OCPD) is identified by normal baseline hemodynamics and normal left ventricular systolic function with a characteristic response to rapid volume infusion. Following the intravenous administration of 1000 ml of normal saline over six to eight minutes, striking elevations of filling pressures are seen; however, diagnosis depends specifically upon a) the development of typical pressure pulse morphology of constriction, b) loss or reversal of respiratory variation of right atrial pressure, and c) precise diastolic equilibration of intracardiac pressures.Nineteen patients with OCPD have been identified in a five year period. Unexplained fatigue, dyspnea and chest pain was the uniform pattern of presentation. Eleven have undergone pericardiectomy resulting in a dramatic symptomatic improvement in all. Each demonstrated gross and/or microscopic evidence of pericardial disease. Recatheterization with volume infusion in five patients following pericardiectomy has revealed return to normal or near normal hemodynamics. This study describes the method for diagnosis of OCPD and recommends pericardiectomy for the management of disabling symptoms.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Fifty patients with acute myocardial infarction were studied serially to evaluate the extent and nature of functional cardiovascular impairment and the time course of recovery. Reinfarction or death occurred in six patients.Peak workload during bicycle exercise in a subgroup of 25 patients with maximal initial test and complete follow-up increased from 334 to 409 kpm/min (P < 0.01) between three and six weeks. There was further significant (P < 0.01) improvement between three and six months from 438 to 488 kpm/min. The incidence of ischemia at a constant workload decreased between three and six weeks without any significant changes in heart rate or blood pressure. Mean cardiac output during exercise at three months was 6.5 and at six months 7.8 L/min (P < 0.05). Corresponding values for stroke volume were 61 and 72 ml (P < 0.05).The data suggest that in clinically stable patients there is an early improvement of the relation between myocardial oxygen supply and demand and a late improvement of functional capacity associated with increased stroke volume and cardiac output.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

To clarify the mechanisms of afterload reduction on left ventricular diastolic function, the influence of nitroglycerin upon ventricular diastolic pressure-volume relations was studied in 22 patients during catheterization. After nitroglycerin, average ventricular systolic pressure declined by 25 mm Hg (18%percnt;) and end-diastolic pressure by 7 mm Hg (28%percnt;) (P < 0.005). End-systolic and diastolic ventricular volumes decreased by 37%percnt; and 23%percnt; respectively (P < 0.005). Although peak negative dP/dt fell by 22%percnt; (P < 0.0005), “T," an index of the time course of isovolumic diastolic ventricular relaxation, was insignificantly changed. Diastolic pressure-volume curves were significantly displaced downward and leftward without significant change in slope, suggesting that a family of pressure-volume curves for each ventricle with similar slope but positions depend upon immediate loading conditions. Absence of change in slope or of “T" suggests that this displacement may be mediated indirectly, perhaps by relaxation of extracardiac constraints to ventricular distensibility. Accordingly, improvement in ventricular function by vasodilators may be partly due to downward displacement of the pressure-volume relation, with associated reduction of wall tension and myocardial oxygen consumption.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Twenty-four patients with aortic valve disease were studied before and 19 ± 12 months following valve replacement with a well functioning prosthesis. Biplane left ventricular angiography and pressures were utilized to determine end-diastolic volume/M2 (EDV), end-systolic volume/m2 (ESV), ejection fraction (EF), left ventricular mass/M2 (LVM) and stroke work (SW). There were nine patients with aortic stenosis (AS), ten patients with combined stenosis and regurgitation (AS-AR), and five patients with aortic regurgitation (AR). Following surgery, patients with regurgitation preoperatively showed marked regression in EDV and ESV. All groups demonstrated regression in LVM. Fifteen patients with a normal EF preoperatively (65 ± 11%percnt;) had no change after surgery; the nine patients with a low EF before surgery (38 ± 8%percnt;) had a normal EF after surgery (60 ± 16%percnt;). We conclude that left ventricular dilatation, hypertrophy, and reduced left ventricular pump function are largely reversible after successful aortic valve replacement.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

We studied 14 patients with cardiac tamponade and pulsus paradoxus; 11 were studied after relief of tamponade by pericardiocentesis. Right ventricular diastolic diameter increased during inspiration in each of 12 patients; left ventricular diastolic diameter decreased during inspiration in each of 13. Mitral valve DE amplitude decreased with inspiration in 13 of 14 patients. Mitral valve E-F slope could be measured in eight patients, and was rounded and not measurable in six. Six of the eight showed inspiratory decrease in mitral E-F slope. Similar changes were observed in two other patients with pulsus paradoxus who had chronic obstructive airway disease. Twenty patients with large pericardial effusions and no tamponade did not show these changes.These results suggest inspiratory augmentation of right ventricular filling and inspiratory diminution of left ventricular filling, not only in cardiac tamponade, but in obstructive airway disease associated with pulsus paradoxus.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

In order to assess the utility of contrast M-mode echocardiography in an intensive care nursery population of critically ill newborns with cardiac and pulmonary disease and to validate contrast echo methods, we performed 200 serial contrast echoes on 40 infants via umbilical arterial or venous catheters which had been placed into these infants for clinical indications. The resulting contrast echoes recorded from the precordium or the suprasternal notch allowed the delineation of intra- and extracardiac right-to-left and left-to-right shunting patterns. Patterns identified and validated by cardiac catheterization (in cardiac patients) were: right-to-left atrial shunts, right-to-left ventricular shunts, and left-to-right patent ductus arteriosus shunts. The studies were without complication. Serial application of these echocardiographic techniques was extremely important in assessing changing physiology in these neonates. Contrast echocardiography adds physiologic flow information to the anatomical information available from M-mode echoes and is quite important in the diagnosis and sometimes in the management of critically ill newborns.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID