Postoperative temperatures and ventricular function.
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Body Temperature↗
Biomedical subjects
J M Matloff
Publications and source records attributed to J M Matloff.
Rate-pressure product correlates poorly with myocardial oxygen consumption during anaesthesia in coronary patients.
In 26 patients having coronary grafts, haemodynamics, coronary sinus blood flow and the arterio-coronary sinus difference of oxygen content were determined, awake and at four intervals during morphine-oxygen or halothane--oxygen anaesthesia. Rate-pressure product (RPP), triple product (TP) and myocardial oxygen consumption (MVO2) were calculated. The correlation of the two indirect indices to MVO2 were tested by repeated measures and regression analyses. No significant correlations were seen at four of five study times, when outlying data points were appropriately excluded. A pitfall of using more than one data point from each patient in the linear regression analysis is pointed out. In addition to the lack of correlation of RPP to MVO2, RPP was an imprecise predictor of myocardial lactate production and of postoperative infarction.
Anesthetics↗
Detection of occult pericardial hemorrhage early after open-heart surgery using technetium-99m red blood cell radionuclide ventriculography.
Pericardial or mediastinal hemorrhage requiring reoperation occurs in 2% to 5% of patients, usually early (0 to 48 hours), after open-heart surgery. This hemorrhage may be occult, and resulting cardiac tamponade may easily be misinterpreted as ventricular dysfunction, common early postoperatively. In such cases, appropriate and timely intervention may not occur. Of 50 patients evaluated by technetium-99m red blood cell gated equilibrium radionuclide ventriculography (RNV) because of early postoperative cardiogenic shock of uncertain etiology, 17 had unique scintigraphic images suggestive of intrathoracic hemorrhage. Of these 17, 5 had a generalized "halo" of abnormal radioactivity surrounding small hyperdynamic right and left ventricles, 11 had localized regions of intense blood pool activity outside the cardiac chambers (two with compression of single chambers), and one demonstrated marked radionuclide activity in the right hemithorax (2000 ml of blood at reoperation). Twelve patients had exploratory reoperation for control of hemorrhage as a direct result of the scintigraphic findings, three were successfully treated with fresh frozen plasma and platelet infusions along with medical interventions to optimize cardiac performance, and two patients died in cardiogenic shock (presumed tamponade) without reoperation. In the 12 reoperated patients, all were confirmed to have active pericardial bleeding. Scintigraphic localization of abnormal blood pools within the pericardium corresponded to the sites at which active bleeding was witnessed at reoperation. The abnormal bleeding was etiologically related to the tamponade state, with marked improvement in hemodynamics after reoperation. Nine additional patients were reoperated for presumed tamponade after RNV revealed an exaggerated halo of photon deficiency surrounding the cardiac chambers.(ABSTRACT TRUNCATED AT 250 WORDS)
Cardiac Surgical Procedures↗
Myocardial infarction during coronary artery bypass surgery--benign event or prognostic omen?
Our observations and experience suggest that an adverse outcome from perioperative infarction occurs predominantly in a defined population of patients. A worsened prognosis and special postoperative interventions need not be anticipated in patients who have simply developed new Q waves after bypass surgery and are free of malignant ventricular arrhythmias and severe degrees of myocardial dysfunction. Furthermore, our data indicates that repeat throacotomy because of bleeding or tamponade early after sustaining a perioperative infarction will adversely affect the outcome of that infarction.
Aged↗
Bileaflet, tilting disc and porcine aortic valve substitutes: in vitro hydrodynamic characteristics.
The desire for a low profile mechanical valve with better fluid dynamic performance led to the design and development of the St. Jude Medical bileaflet prosthesis. Comparative in vitro flow studies indicate that it has better pressure drop characteristics than the Björk-Shiley (convexo-concave) and Carpentier-Edwards porcine valves in current clinical use, especially in the small sizes. In the 21 to 27 mm aortic valve size range the St. Jude valve has an average performance index of 0.66, compared with 0.46 and 0.32 for the Björk-Shiley and Carpentier-Edwards valves, respectively. In contrast, the St. Jude valve has larger regurgitant volumes than both the Björk-Shiley and Carpentier-Edwards valves. Velocity measurements with a laser-Doppler anemometer indicate relatively centralized flow with small amounts of turbulence downstream of the St. Jude valve. The flow is unevenly distributed between the central and side orifices. The turbulent shear stresses are, however, large enough to cause sublethal or lethal damage to blood elements. Wall shear stresses are smaller than those measured downstream of the Björk-Shiley valve. Regions of flow separation were observed just downstream from the sewing ring, which could lead to excess tissue growth along the sewing ring. The results of this study indicate that overall in vitro fluid dynamic performance of the St. Jude valve is superior to that of the two other commonly used prostheses.
Animals↗
Bileaflet, tilting disc and porcine aortic valve substitutes: in vivo hydrodynamic characteristics.
The St. Jude valve is a new bileaflet disc cardiac valve prosthesis designed to avoid some of the hemodynamic drawbacks of other prostheses. The in vivo flow characteristics of the St. Jude aortic valve (42 patients) were studied and compared with those of three other commonly used aortic prostheses. Björk-Shiley (12 patients), Hancock (27 patients) and Carpentier-Edwards (15 patients). The studies, performed 24 to 48 hours after surgery, included measurements at rest and during augmentation of valve flow by infusion of isoproterenol. The mean performance index for valves of all sizes is higher for the St. Jude than for either porcine valve, both at rest and during isoproterenol infusion (p less than 0.05). Utilizing data both at rest and with isoproterenol, the relation of valve flow and mean systolic gradient for each size of St. Jude valve (19 to 25 mm) indicates the occurrence of small increases in gradient (5.3 to 8.2 mm Hg) as valve flow increases, ranging from 161 to 436 ml/systolic X min. A direct comparison of valve flow and gradient data for all size 25 and 23 mm prostheses at rest indicates a tendency for a lower mean systolic gradient in both mechanical valves than in either porcine valve (p = 0.07). With isoproterenol augmentation of valve flow in 25 mm valves, the gradient is less (p less than 0.05), and the effective orifice area and performance index are larger (p less than 0.05) for the St. Jude than for either porcine valve.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Coping with transient intellectual dysfunction after coronary bypass surgery.
In summary, we believe that the impact of our findings on the patient and clinician includes recognition and acknowledgment that transient cognitive dysfunction frequently follows coronary bypass surgery. With this recognition comes the reassurance to the patient and his family that it is a temporary phenomenon that should resolve in time. To help the patient comply with his postoperative instructions during this difficult time period, there should be individual, slow-paced presentation of material with intentional repetition of information to help him remember the specific details of his postoperative instruction; the individual most involved with assisting in the patient's postoperative recovery should be included in all teaching sessions; and instructive audiovisual material should be used in postoperative home care.
Adaptation, Psychological↗
The St. Jude Medical bileaflet valve prosthesis. A 5 year experience.
A 5 year experience with the bileaflet St. Jude Medical valve is reported. Between March, 1978, and June, 1982, 198 patients received 233 such valves (90 mitral, 73 aortic, and 35 double mitral-aortic valve replacements). Total follow-up was 4,896 patient-months; survivors were followed up for 1 to 5 years (mean 35 months). Early (30 day) mortality was 6.6% overall and 11.1% after mitral, 2.7% after aortic, and 2.9% after double valve replacement. Total late mortality was 15.2%; the actuarial survival rate at 4 years was 67% after mitral, 79% after aortic, and 79% after double valve replacement. Ischemic mitral valve disease was associated with an early mortality of 26.7% and a 4 year survival rate of 34%; without this high-risk subset, early mortality was 3.3% and the 4 year survival rate was 77% after mitral valve replacement. A multivariate logistic regression model identified three preoperative patient characteristics associated with increased postoperative mortality: ischemic mitral valve disease (p less than 0.001), a depressed left ventricular ejection fraction (less than 55%; p less than 0.05), and advanced New York Heart Association class (IV; p less than 0.05). Valve-related complications occurred in 14 patients (3.4% per patient-year). There were no instances of primary structural failure or hemolysis. Thromboembolism (nine patients, 2.2% per patient-year) occurred more frequently after double (3.7% per patient-year) or mitral valve replacement (2.3% per patient-year) than after aortic valve replacement (1.3% per patient-year) and more frequently in 12 patients receiving aspirin and dipyridamole (6.5% per patient-year) than in 173 patients receiving warfarin (1.9% per patient-year). No thromboembolic event was fatal. Reoperation was necessary because of one valve thrombosis, one valve erosion, and two perivalvular leaks due to endocarditis; three of the four patients survived reoperation (one valve-related death, 0.5%). Of 154 patients alive at latest follow-up, 85% were in New York Heart Association Class I or II, and 90% had improved by at least one class. This intermediate experience with the St. Jude Medical valve indicates that, in addition to its previously demonstrated excellent hemodynamic performance, there have been no instances of primary structural failure or hemolysis. Warfarin anticoagulation is recommended in all patients.
Adolescent↗
Mitral valve replacement: impact of coronary artery disease and determinants of prognosis after revascularization.
From 1969 to 1982, 419 patients underwent single mitral valve replacement; of these, 48% had associated coronary artery disease (9% single vessel, 8% double vessel, 28% triple vessel, 3% left main). In 216 patients with no associated coronary disease, in 179 patients with coronary disease that was revascularized, and in 24 patients with coronary disease that was not revascularized, the 30 day mortalities were 4.2%, 13.9%, and 29.2% (p less than .05) after valve replacement. Actuarial survivals at 8 years were 68%, 44%, and 15%, respectively (p less than .01), with 1 to 165 months of follow-up (mean 52). After matching the three cohorts of patients in age, sex, left ventricular ejection fraction, and valve lesion, the presence of associated coronary artery disease decreased long-term survival and revascularization improved survival (p less than .05 for both). Incidental coronary disease in patients with rheumatic mitral valve disease had a significant negative influence on survival if left unbypassed (p less than .05); after revascularization and valve replacement, the 30 day mortality was 7.3% and the 8 year survival was 52%. Coronary disease etiologically related to ischemic mitral regurgitation identified a high-risk group of patients, with a 30 day mortality of 19.6% and an 8 year survival of 37% after the combined procedure. A multivariate logistic regression model was used to determine which preoperative and intraoperative variables predicted early and late outcome after combined mitral valve replacement and coronary revascularization. Predictors of early death were advanced age (greater than 60 years), New York Heart Association functional class (IV), an ischemic etiology of the mitral valve disease, and a depressed left ventricular ejection fraction (less than 55%). Predictors of late death were triple-vessel or left main coronary disease, increased left ventricular end-diastolic volume (greater than 120 ml/m2), and depressed left ventricular ejection fraction (less than 55%). These findings highlight the important etiologic and prognostic role of coronary artery disease in patients requiring mitral valve replacement.
Adolescent↗
Regional distribution of pulmonary blood volume: an index of pulmonary capillary wedge pressure determined from blood pool scintigraphy.
Progressive redistribution of pulmonary blood flow to the lung apices occurs with increasing degrees of left ventricular failure, and correlates with increasing pulmonary capillary wedge pressure (PCWP). If similar changes in pulmonary blood volume (PBV) occur, then technetium-99m equilibrium blood pool scintigraphy, by assessing relative distribution of PBV, may allow prediction of PCWP. Therefore 30 patients being monitored with pulmonary artery balloon flotation catheters underwent imaging. PCWP was compared with the average radioactive count density arising from apical (A) and basal (B) regions of interest within the right lung, expressed as an A/B ratio. Correlation was strong for patients imaged erect, either posteriorly (r = 0.864, p = 0.001) or in the 45 degrees left anterior oblique position (r = 0.842, p = 0.001), and only slightly less impressive for patients imaged supine (r = 0.678, p = 0.001). Especially when imaging was performed with patients erect, an A/B ratio greater than unity identified with high sensitivity (100%) and specificity (83 to 88%) an abnormally elevated PCWP (greater than 12 mm Hg). Moreover, directional changes in the A/B ratio reflected concomitant changes in PCWP after intervention. Thus, analysis of lung A/B radioactive count ratios obtained by equilibrium blood pool scintigraphy may be used to evaluate PCWP.
Adult↗
Noninvasive detection of active pericardial bleeding using cardiac blood pool scintigraphy.
The diagnosis of active pericardial bleeding has traditionally depended on an invasive documentation by needle aspiration, angiography, or direct inspection. Blood pool scintigraphy performed in 2 patients just before and after the development of hemopericardium revealed unique images in which acute pericardial bleeding manifested itself by an additional blood pool adjacent to the cardiac chambers. With appropriate attention to technical factors, such distinctive images should be highly specific for active bleeding into the pericardial sac.
Aged↗
Nitrous oxide added to halothane reduces coronary flow and myocardial oxygen consumption in patients with coronary disease.
The haemodynamic and myocardial metabolic effects of adding 50 per cent nitrous oxide to 0.5 per cent halothane were studied in 13 patients, before the surgical incision for coronary artery vein grafts. Cardiac output and coronary sinus blood flow were determined by thermodilution, along with haemodynamic measurements. Measurements 15 minutes after addition of nitrous oxide revealed a significant decrease in heart rate, arterial pressure, cardiac index, coronary sinus blood flow and myocardial oxygen consumption. There was a significant increase in coronary sinus lactate content, and a significant decrease, from 27 to 11 per cent, in myocardial lactate extraction. We conclude that these circulatory changes were likely to be due to a depression of ventricular function by the nitrous oxide. The myocardia of these patients with severe coronary disease were becoming globally ischaemic while they were receiving 50 per cent oxygen, in the presence of hypotension. Nitrous oxide should be turned off when hypotension occurs in coronary patients.
Coronary Artery Bypass↗
Myocardial and systemic effects of nitroglycerin, given awake and during anaesthesia in coronary patients.
The haemodynamic and myocardial energy-metabolic effects of intravenous nitroglycerin (NTG) were investigated in seven male patients about to undergo coronary artery bypass grafting. Effects of one mg of NTG given at a rate of 100 micrograms . min-1 to sedated, awake hypertensive patients, were compared to effects of the same dose of NTG in the same patients, after sternotomy. Coronary sinus flow was measured by a thermodilution catheter and myocardial oxygen consumption (MVO2) was calculated using the arterio-coronary sinus difference of oxygen content. With the patients awake, cardiac index and stroke volume and work indices fell during NTG administration. There was only a small fall in arterial pressure as heart rate and systemic resistance increased. Pulmonary capillary wedge pressure decreased but not MVO2. With NTG administration during anaesthesia, arterial pressure fell significantly to normal, as systemic resistance decreased, without a change in heart rate or cardiac index. Calculated MVO2 decreased as the arterial-coronary venous difference of oxygen content increased. Both oxygen and lactate balance of the myocardium were maintained. NTG given during anaesthesia was more effective in reducing blood pressure and MVO2 than when given to awake patients.
Adjuvants, Anesthesia↗
The role of cardiac surgery in acute myocardial infarction. I. With mechanical complications.
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Heart Rupture↗
The role of cardiac surgery in acute myocardial infarction. II. Without mechanical complications.
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Arrhythmias, Cardiac↗
CK-MB release following coronary artery bypass grafting in the absence of myocardial infarction.
Elevation of levels of the myocardial-specific isoenzyme of creatine kinase (CK-MB) in the immediate postoperative period in patients undergoing coronary artery bypass grafting is usually associated with myocardial necrosis. However, mean isoenzyme elevations of 18 +/- 2 IU/L (standard error of the mean) were recently observed in 6 patients in the absence of electrocardiographic or scintigraphic (technetium 99m stannous pyrophosphate) evidence of perioperative myocardial infarction. To test the hypothesis that surgical trauma of the atrium and aorta during cannulation for cardiopulmonary bypass might contribute to elevated CK-MB levels, biopsy of the right atrial appendage and aorta of 7 patients was done at operation, the tissue samples were assayed for total creatine kinase (CK) activity using the Rosalki technique, and for CK-MB using column chromatography. The results indicate that the human atrium is a rich source of CK, with the proportion of CK-MB similar to that present in the ventricle (20%). In addition, technical considerations inherent in the performance of coronary bypass surgery may result in release of CK-MB, causing elevated serum enzyme levels in the post-coronary artery bypass patient in the absence of myocardial infarction.
Aorta↗
Effect of intraoperative MI on late survival after CABG.
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Coronary Artery Bypass↗
Right ventricular function during left heart bypass.
Right heart failure may occur during mechanical support of the left ventricle (LV). Right ventricular (RV) functional changes were studied in eight dogs (26.9 +/- 1.4 kg) subjected to various degrees of left heart bypass (LHBP) with a roller pump. The venous return to the right atrium was controlled with a second pump. RV function was evaluated by peak RV developed pressure, its first derivative (dp/dt), and mean RA pressure measurements. Left atrial, LV, and aortic pressure and both roller pump flows were determined. Incremental increases in LHBP flow ratio ([LHBP flow x 100] divided by venous return flow) to 60%, 90%, and 100% were associated with decrements in RV dp/dt from the control of 212 +/- 17 torr/sec to 192 +/- 16, 178 +/- 16, and 168 +/- 13 torr/sec, respectively. Biventricular bypass or total cardiopulmonary bypass with extracorporeal membrane oxygenation seems to be indicated if LHBP flow ratio greater than 90% is required to maintain adequate body perfusion. Maximal LV decompression to obtain the greatest reduction of LV myocardial oxygen consumption may not be the ideal goal during LV mechanical assistance.
Animals↗