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Biomedical subjects

M Galinanes

Publications and source records attributed to M Galinanes.

9 recordsLinked to original sources
PubMed1996

Dichotomy of ischemic preconditioning: improved postischemic contractile function despite intensification of ischemic contracture.

BACKGROUND: Acceleration of ischemic contracture is conventionally accepted as a predictor of poor postischemic function. Hence, protective interventions such as cardioplegia delay ischemic contracture and improve postischemic contractile recovery. We compared the effect of ischemic preconditioning and cardioplegia (alone and in combination) on ischemic contracture and postischemic contractile recovery. METHODS AND RESULTS: Isolated rat hearts were aerobically perfused with blood for 20 minutes before being subjected to zero-flow normothermic global ischemia for 35 minutes and reperfusion for 40 minutes. Hearts were perfused at a constant pressure for 60 mm Hg and were paced at 360 beats per minute. Left ventricular developed pressure and ischemic contracture were assessed with an intraventricular balloon. Four groups (n=8 hearts per group) were studied: control hearts with 35 minutes of unprotected ischemia, hearts preconditioned with one cycle of 3 minutes of ischemia plus 3 minutes of reperfusion before 35 minutes of ischemia, hearts subjected to cardioplegia with St Thomas' solution infused for 1 minute before 35 minutes of ischemia, and hearts subjected to preconditioning plus cardioplegia before 35 minutes of ischemia. After 40 minutes of reperfusion, each intervention produced a similar improvement in postischemic left ventricular development pressure (expressed as a percentage of its preischemic value: preconditioning, 44 +/- 2%; cardioplegia, 53 +/- 3%; preconditioning plus cardioplegia, 54 +/- 4% and control, 26 +/- 6%, P<.05). However, preconditioning accelerated whereas cardioplegia delayed ischemic contracture; preconditioning plus cardioplegia gave an intermediate result. Thus, times to 75% contracture were as follows: control, 14.3 +/- 0.4 minutes; preconditioning, 6.2 +/- 0.3 minutes; cardioplegia 23.9 +/- 0.8 minutes; and preconditioning plus cardioplegia 15.4 +/- 2.4 minutes (P<.05 preconditioning and cardioplegia versus control). In additional experiments, using blood- and crystalloid-perfused hearts, we describe the relationship between the number of preconditioning cycles and ischemic contracture. CONCLUSIONS: Although preconditioning accelerates, cardioplegia delays, and preconditioning plus cardioplegia has little effect on ischemic contracture, each affords similar protection of postischemic contractile function. These results question the utility of ischemic contracture as a predictor of the protective efficacy of anti-ischemic interventions. They also suggest that preconditioning and cardioplegia may act through very different mechanisms.

Animals↗
PubMed1993

Pulmonary banding complicated by low origin of right pulmonary artery.

In our attempt to band the main pulmonary artery above the valve in a 4-month-old prematurely born infant, we erroneously banded only the left pulmonary artery, owing to the unusually low origin of the right pulmonary artery (which arose partially in the sinus of Valsalva). When severe cardiac failure recurred, the anomaly was noted upon reoperation and the band was repositioned at the level of the pulmonary valve. Since this revision, the postoperative course has been good. Low origin of the right pulmonary artery is normal in premature infants. However, origin of the right pulmonary artery from the sinus of Valsalva is a sufficiently extreme variant to constitute a surgically important anomaly. Our postmortem studies of the pulmonary arteries of 25 premature infants born without cardiac malformation showed that while the right pulmonary artery was lower than the left, it never originated from the sinus of Valsalva. This anomalous configuration of the pulmonary arteries has, to our knowledge, never been found in an infant as old as 4 months; yet we believe it should be taken into account when banding pulmonary arteries in infants.

Cardiac Output, Low↗
PubMed1990

The consequences of asanguineous versus sanguineous reperfusion after long-term preservation of the heart.

We have used the heterotopically transplanted rat heart to investigate whether the nature (sanguineous or asanguineous) of the initial period of reperfusion after hypothermic cardioplegic storage influences the postischaemic recovery of the heart. Excised rat hearts were arrested by infusion (1 min at 25 degrees C followed by 2 min at 7.5 degrees C) with the St Thomas' Hospital cardioplegic solution, subjected to 4 h of storage at 7.5 degrees C and heterotopically transplanted over a fixed period of 45 min. Reperfusion was then carried out for 80 min according to one of the following protocols: 60 or 20 min of blood perfusion in situ followed by excision, and 20 or 60 min of in vitro perfusion with crystalloid solution (Groups I and II, respectively) or immediate excision and 80 min of crystalloid perfusion (Group III). Intraventricular balloons were used to define pressure-volume relationships at the end of the 80 min period of reperfusion. Tissue samples were then taken for assessment of water content, adenosine triphosphate (ATP) and creatine phosphate (CP) content. Mean left ventricular developed pressure (at a loading volume of 110 microliters) was 92 +/- 6, 79 +/- 6 and 51 +/- 6 mmHg in Groups I, II and III, respectively. Left ventricular end-diastolic pressure was lower in the initial blood reperfusion groups (25 +/- 4 and 21 +/- 3 mmHg in Group I and II, respectively, compared with 37 +/- 5 mmHg in Group III).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Assessment of ischemic injury and protective interventions: the Langendorff versus the working rat heart preparation.

The isolated rat heart is widely used for investigating ischemia and evaluating protective interventions, particularly with global ischemia, in which Langendorff and working preparations have formed the cornerstone of much of the developmental work on cardioplegic solutions. The objective of the present study was to compare the vulnerability of the two preparations to global ischemia and their responsiveness to protection with the St Thomas' Hospital cardioplegic solution. Langendorff preparations (n = 6) were subjected to 15, 30, 45, 60, 75, 90, 105 or 120 mins of global ischemia, and working preparations (n = 6) to 10, 15, 20, 25, 30, 35, 40 or 45 mins of global ischemia; post ischemic recovery of cardiac function, creatine kinase leakage, tissue ATP and creatine phosphate content were measured. With 30 mins of global ischemia, the impairment of cardiac function was similar in both preparations. With reperfusion in the Langendorff, the left ventricular developed pressure (LVDP), maximum rate of pressure development (dP/dt), heart rate and coronary flow recovered to 54.7 +/- 5.7, 53.7 +/- 7.1, 88.9 +/- 3.0 and 67.2 +/- 1.8%, respectively, of their pre-ischemic control value. In working hearts, cardiac output, heart rate and coronary flow recovered to 17.9 +/- 2.5, 95.6 +/- 4.2 and 73.8 +/- 8.2%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Diltiazem and progression of myocardial ischemic damage during coronary artery occlusion and reperfusion in porcine hearts.

This study was designed to investigate whether a cardioprotective intervention could delay the completion of necrosis so that subsequent reperfusion would be more useful. Thirty-six pigs were randomly allocated to treatment with diltiazem (15 micrograms/kg per min) or saline solution and to a 60 or 120 minute coronary occlusion period followed by reperfusion. The treatment was begun 15 minutes before coronary occlusion and terminated 75 minutes after reperfusion. Twenty-four hours after the procedure, the heart was sliced and incubated in triphenyltetrazolium chloride. The infarct area and the maximal transmural area of extension of the infarct were calculated by planimetry. The total number of red blood cells in a transmural section was also counted. In the pigs with a 60 minute coronary occlusion, diltiazem (compared with saline solution) significantly reduced infarct size from 9.7 +/- 1.5% of left ventricular mass to 5.9 +/- 0.6% (p less than 0.05) and the percent transmural extension from 0.72 +/- 0.05 to 0.61 +/- 0.05% (p less than 0.05). Red blood cell extravasation in the infarcted area was reduced from 161,934 +/- 59,905 to 78,525 +/- 46,484 cells/mm3 (p less than 0.05) with diltiazem and the percent transmural extension of the hemorrhagic necrosis from 70 +/- 10 to 36 +/- 15% (p less than 0.05). No such differences were observed in the 120 minute coronary occlusion groups. Mean red blood cell counts and the extent of hemorrhagic necrosis did not correlate with either infarct size or transmural extension.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Surgical repair of superoinferior ventricles: experience with 3 patients.

Superoinferior ventricles are a rare anomaly characterized by a horizontal ventricular septum and a hypoplastic right ventricular sinus localized anterosuperiorly to the left ventricle. This anomaly frequently is accompanied by malformation of the atrioventricular valves. A large ventricular septal defect is always present, and anomalies of the ventriculoarterial relations are common. The results of surgical repair of this complex lesion have been poor. Our recent surgical experience with 3 patients, 2 of whom are well 36 and 38 months postoperatively, suggests a hopeful outcome for the repair of this complex anomaly. The surgical approach was different in each of the 3 patients, demonstrating the need for a precise echocardiographic and angiocardiographic preoperative description of the cardiac anatomy to appropriately repair the multiple variants of this complex anomaly.

Angiocardiography↗
PubMed1985

Surgical treatment of the post-infarction left ventricular aneurysm. Factors influencing early and late results.

The early and late results of a 4 year surgical experience with 119 left ventricular aneurysms (LVA) are analyzed. The most common indication for surgery was angina in 78 patients, congestive heart failure (CHF) in 34, arrhythmia in 5 and recurrent embolism in 1. One patient was operated on prophylactically. There were 112 "anterior" and 7 "posterior" aneurysms. Preoperative ventricular function was significantly worse in the CHF group. LVA resection was carried out in 105 patients and a plicature in other 14. In 92 cases the procedure was combined with a myocardial revascularization. Additional cardiac procedures were performed in 14 patients. Overall early (5.9%) and late mortality (18.7%) was significantly higher in the CHF group than in the angina group (14.7% versus 1.3%, p less than 0.01, and 37.9% versus 12.9%, p less than 0.01, respectively). Associated surgical procedures (p less than 0.001) and acuity of the LVA (p less than 0.05) also increased the operative risk. The 5 year-survival was better for the angina group (85.7 +/- 4%) and arrhythmias group (80 +/- 22%) than for CHF patients (46.7 +/- 19%) (p = 0.052). Functional improvement was uniform between survivors of all groups (73.2%). In 15 patients with pre- and postoperative studies hemodynamic parameters were found improved although only a global contractile score did reach significant levels (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Complications of circulatory assistance with intra-aortic balloon pumping: a comparison of surgical and percutaneous techniques.

One hundred and two consecutive patients who underwent circulatory support with intra-aortic balloon pumping were reviewed. All patients underwent surgery for coronary bypass, resection of ventricular aneurysm, or valve replacement. Circulatory assistance was initiated preoperatively in 21 patients and postoperatively in 81 patients. Insertion of the balloon catheter was attempted randomly by the surgical technique or by the percutaneous method in 47 patients each. The surgical insertion failed in five patients (10.6%), and the percutaneous method was a failure in four patients (8.5%). All failures with both techniques occurred when catheter insertion was attempted postoperatively. Among 85 patients studied for complications, there were 17 vascular and 3 wound complications (23.5%). The complication rate with the surgical technique was 11.4% and that of the percutaneous insertion 30.6%, a difference that is significant. The mean duration of circulatory support was significantly longer in patients who developed vascular complications (123 hours vs 78 hours). Vascular complications resulted in the loss of limb in two patients, one in each group. There were two deaths directly related to the use of circulatory assistance, one from perforation of the iliac artery and one from acute renal failure following revascularization of a severely ischemic limb, both in the percutaneous group. Thus, percutaneous balloon insertion has a failure rate similar to surgical insertion but a higher rate of complications, partly caused by percutaneous removal of the catheter. Practical recommendations are made in regard to the use and management of the technique.

Acute Kidney Injury↗