Doppler-derived left ventricular rate of pressure rise determination in presence of severe acute mitral regurgitation in pigs.

Doppler-derived left ventricular (LV) rate of pressure rise (Dop LV DeltaP/Deltat) is described as an index of LV performance in the presence of mitral regurgitation (MR). This study was designed to define more accurately the accuracy of the method in the presence of severe MR. Ten pigs were anesthetized and monitored. MR was gradually created. At each grade of MR, preload was manipulated with the intent of modifying LV end-diastolic area value within a range of +/-20%. Concurrently, the mean left atrial pressure (LAP) was recorded, MR was quantified by the mitral to aortic velocity-time integral ratio (mitroaortic VTI ratio), Dop LV DeltaP/Deltat was calculated, and peak LV dP/dt was derived from LV catheterism data. During the procedure Dop LV DeltaP/Deltat gradually underestimated peak LV dP/dt. This difference was correlated to the mean LAP (P < 10(-5)) and mitroaortic VTI ratio (P < 10(-5)) and became clinically significant when the mean LAP was superior to 21 mm Hg.

Pulsed Doppler intraoperative flow assessment and midterm coronary graft patency.

BACKGROUND: This study was designed to assess the value of hemodynamic measurements taken intraoperatively in predicting midterm patency of coronary bypass grafts. METHODS: A pulsed Doppler flowmeter was routinely used during operation to determine the hemodynamic parameters of coronary bypass grafts. During a 7-year period, 85 patients underwent angiographic evaluation. As a result, a thorough hemodynamic assessment of 214 grafts (89 arterial and 125 venous) at initial operation was available for analysis. RESULTS: The overall patency rate was 88.3%. The mean flow measured intraoperatively in 168 intact grafts was 60+/-3 mL/min (range, 9 to 230 mL/min), and the resistance was 1.8+/-0.1 peripheral resistance units (range, 0.3 to 9.0 peripheral resistance units). The mean flow was 36+/-5 mL/min (range, 2 to 107 mL/min), and the resistance was 5.9+/-2.0 peripheral resistance units (range, 0.6 to 46.0 peripheral resistance units) in 25 grafts found occluded at angiographic evaluation. Multivariate analysis identified three independent variables associated with a reduced patency rate: increased resistance as measured in the graft (p = 0.012), increasing interval of control angiography (p = 0.006), and preoperative cardiogenic shock (p = 0.040). CONCLUSIONS: The prognosis for midterm patency of aortocoronary bypass grafts depends on the intraoperative hemodynamic status.

Hemodynamic benefit of optimizing atrioventricular delay after cardiopulmonary bypass.

BACKGROUND: Shortening of atrioventricular delay (AVD) by sequential cardiac pacing has been proposed to improve hemodynamics in patients with end-stage heart failure. In addition, optimization of prolonged AVD may be associated with a decrease of presystolic mitral insufficiency. The aim of this study was to explore the incidence of prolonged AVD during the early postcardiopulmonary bypass (CPB) period and to evaluate the hemodynamic benefit of its shortening by using sequential cardiac pacing. METHODS: Fifty consecutive patients scheduled for coronary artery bypass grafting were prospectively screened. AVD was measured immediately after separation from CPB. Patients presenting with AVD greater than or equal to 200 ms entered the study. Sequential cardiac pacing was introduced with programmed AVD starting at 80 ms and randomly increased by steps of 20 ms until resumption of native anterograde atrioventricular node conduction. Cardiac index (CI) was derived from transesophageal echocardiographic data during each step of this procedure. RESULTS: Nineteen patients were included. Median native AVD was 220 ms. Median optimal AVD was 140 ms. Mean native CI (CI-nat) was 2.59 +/- 0.42 L/min/m2. Mean optimal CI (CI-opt) was 3.12 +/- 0.45 L/min/m2. CI-opt/CI-nat was 1.20 +/- 0.07. CI-opt/CI-nat was significantly inversely correlated with preoperative left ventricular ejection fraction (r = -0.83). CONCLUSIONS: Prolonged AVD is a common occurrence after CPB. Its artificial shortening by sequential cardiac pacing is always associated with a significant increase of CI. The magnitude of this hemodynamic improvement is inversely correlated with preoperative left ventricular ejection fraction.

Persistent left superior vena cava: transoesophageal echocardiographic findings and surgical strategies.

Two cases of casual discovery of persistent left superior vena cava during cardiac surgery are reported. Diagnoses were suspected at the time of peroperative transoesophageal echocardiography in the first case, and of preoperative fluoroscopy during a Swan-Ganz catheter insertion procedure in the second case. For both patients, a peroperative echo contrast study permitted to confirm the anomaly before initialization of cardiopulmonary bypass. Embryology, echocardiographic findings and surgical management, including cardioplegia delivering and left upper venous system drainage, are reviewed.

Assessment of continuous cold blood cardioplegia in coronary artery bypass grafting.

BACKGROUND: A method of cold blood cardioplegia (CBCP) delivered continuously and in a retrograde manner was compared with methods differing only by their rate (intermittent) or way (antegrade) of administration. METHODS: This study comprises 298 consecutive patients undergoing isolated coronary artery bypass grafting procedures performed by the same surgeon from 1992 to 1995. Three-vessel disease characterized 58.8% of the cases, and the left ventricular ejection fraction was less than 0.40 in 22.8%. In group I (n = 100), CBCP was administered in an antegrade and intermittent fashion; in group II (n = 87), CBCP was given in a retrograde and intermittent manner; in group III (n = 111), CBCP delivery was retrograde and continuous. RESULTS: The incidence of major cardiac adverse outcome (death or need for intraaortic balloon counterpulsation) was 7.0% in group I, 8.0% in group II, and 0.9% in group III (p = 0.040). Repeated-measures analysis of hemodynamic indices showed a marked superiority of continuous retrograde compared with antegrade intermittent blood cardioplegia regarding left ventricular stroke work index (p < 10(-4)) and compared with both methods of intermittent CBCP regarding right ventricular stroke work index (p < 10(-5)). CONCLUSIONS: The use of continuous CBCP resulted in a significant reduction in major cardiac events, better left ventricular performance, and a marked improvement of right ventricular function in comparison with similar solutions of blood cardioplegia administered intermittently, independent of their way of delivery.

Unusual pitfall of use of retrograde cardioplegia.

The use of retrograde cardioplegia can lead to several complications, mainly related to injuries during the cannulation of the coronary sinus. We herein present a case report of injury to the right coronary artery related to kinking due to the pursestring on the right atrium.

Operation for unstable angina pectoris: factors influencing adverse in-hospital outcome.

Coronary artery bypass grafting for the treatment of unstable angina is still associated with increased operative risk and postoperative morbidity. The impact of the extended use of arterial grafts on early results is incompletely defined. In a 7-year period (1986 to 1993), 474 patients (average age, 65 years; range, 34 to 85 years) underwent coronary artery bypass grafting for the treatment of unstable angina. Sixty-eight patients were operated on emergently and 406 urgently. They received an average of 3.0 distal anastomoses (range, 1 to 6). Seventy-nine patients had exclusively venous grafts, 316 had one internal thoracic artery graft, 79 had bilateral internal thoracic artery grafts, and 20 had inferior epigastric artery grafts. Sequential internal thoracic artery grafting was performed in 70 patients. Redo operations were performed in 26 patients. Thirty-four patients (7.2%) experienced a new myocardial infarction. Eighty-nine patients (18.8%) had an intraaortic balloon pump inserted preoperatively, intraoperatively, or postoperatively. Eight patients (1.7%) died intraoperatively and 24 patients (5.1%) died postoperatively. Seventy-seven patients (16.2%) had an adverse outcome, as shown by the need for an intraaortic balloon pump (intraoperatively or postoperatively) or hospital death, or by both. Forty variables were examined by multivariate analysis for their influence on the occurrence of an adverse outcome. Aortic cross-clamp time (p = 0.0004), transfer from the intensive care unit (p = 0.0023), female sex (p = 0.0023), operation performed in early years (p = 0.0041), left ventricular aneurysm (p = 0.0068), the number of diseased coronary vessels (p = 0.0312), and reoperation (p = 0.0318) were all found to be significant independent predictors of increased risk.(ABSTRACT TRUNCATED AT 250 WORDS)