Effects Of Pericardiectomy Research Articles

Effects of pericardiectomy on training- and myocardial infarction-induced left ventricular hypertrophy, chamber dimensions and gene expression.

The primary purpose of the study was to evaluate whether a pericardiectomy (PERI) alters training- or myocardial infarction (MI)-induced left ventricular hypertrophy (LVH), chamber geometry, gene expression and/or running performance. Mice were randomized into 6 groups: naïve control (CONT)-sedentary (Sed), CONT-trained (Tr), PERI-Sed, PERI-Tr, MI-Sed and MI-Tr. MI mice also received a pericardiectomy as part of the MI surgical procedure. 10 weeks of treadmill running resulted in enhanced running performance-to-exhaustion in all 3 trained groups (CONT-Tr, PERI-Tr, MI-Tr) compared to sedentary cohorts (P<0.001). Training also resulted in similar increases in normalized LVH (LV/BW) in CONT-Tr and PERI-Tr mice. 2D-echocardiographic evaluation of LV internal chamber dimensions revealed that stroke diameter (SD) was larger in PERI compared to MI (P<0.01) but not CONT mice. Ventricular B-type natriuretic peptide mRNA (BNP) was elevated only in the 2 MI groups. Left ventricle β1-adrenergic receptor (β1-AR) and melusin transcripts both demonstrated an overall increase in trained compared to sedentary mice (both P<0.05). Additionally long-term pericardiectomy did not further enhance running performance or increase LV/BW in either sedentary or trained mice.

GW26-e3992 Long-term Effects of Pericardiectomy on Left Ventricular Mechanics in Patients with Constrictive Pericarditis

GW26-e3992 Long-term Effects of Pericardiectomy on Left Ventricular Mechanics in Patients with Constrictive Pericarditis

Effects of pericardiectomy on early diastolic mitral annular velocity in patients with constrictive pericarditis

Background In patients with constrictive pericarditis (CP), early diastolic mitral annular velocity (E') is usually normal or exaggerated due to limitation of lateral expansion by the constricting pericardium. Although pericardiectomy is the treatment of choice for CP, it is difficult to evaluate its effectiveness. Theoretically, E' may decrease after successful pericardiectomy. However, little data are available regarding the effect of pericardiectomy on E'. The purpose of this study was to assess the change in E' after pericardiectomy in patients with CP. Methods We studied 16 patients (12 males, mean age 62.3 ± 7.0 years) with surgically confirmed CP for changes in pre-discharge Doppler parameters following pericardiectomy. CP was secondary to previous cardiac surgery in 4 patients, tuberculosis in 4 patients, radiation-induced in 1 patient, and idiopathic in 7 patients. Ten patients underwent complete pericardiectomy (62.5%). E' was measured at the septal annulus before pericardiectomy and a mean duration of 10 (± 6) days after. Results E' significantly decreased from 9.2 ± 2.7 cm/s to 7.4 ± 2.6 after pericardiectomy ( p = 0.013). The mean percent change of E' after pericardiectomy was 17.9 ± 25.9%. The decrement of E' was significantly higher in patients with complete pericardiectomy than in patients who underwent a partial pericardiectomy (2.7 ± 2.3 vs. 0.4 ± 2.1, p = 0.042). Also, more than 15% decrease of E' was significantly higher in patients with improvement of symptom after pericardiectomy (9 (100.0%) vs. 3 (42.9%), p = 0.019). Conclusion E' decreased following pericardiectomy in most of the patients with CP. The change of E' after pericardiectomy may be useful in evaluating the effectiveness of pericardiectomy.

Influence of pericardium on left atrial compliance and pulmonary venous flow.

We studied seven open-chest anesthetized dogs to test the hypothesis that left atrial (LA) compliance is increased after pericardiectomy and to determine the effect of pericardiectomy on left atrial reservoir and conduit function. Two orthogonal sonomicrometer crystal pairs were used to estimate LA volume, and LA filling was assessed with a pulmonary vein (PV) flow probe. The left ventricular (LV) systolic (JFTI) and diastolic (KFTI) PV flow integrals were used as indexes of LA reservoir and conduit function, respectively. Diastolic LV transmitral flow was assessed with transesophageal Doppler echocardiography. Data were acquired over a wide range of intracardiac pressures and volumes obtained by intravenous hetastarch infusion both before and after pericardiectomy. The mean dynamic stiffness constant of the LA diastolic pressure-volume relation was significantly greater before pericardiectomy than afterwards (0.15 +/- 0.04 vs. 0.08 +/- 0.03 ml-1, P < 0.05). Data were analyzed before and after pericardiectomy at three matched levels of left atrial pressure (LAP; 7, 13, and 20 mmHg). The J-to-KFTI ratio increased significantly with volume infusion and was significantly less after pericardiectomy than before (1.2 +/- 0.7 vs. 1.2 +/- 0.6, 1.8 +/- 0.6 vs. 2.2 +/- 0.9, and 2.0 +/- 0.8 vs. 2.6 +/- 0.9 at low, mid, and high levels of LAP, respectively; P < 0.05 at mid and high levels of LAP). Peak early transmitral velocity increased with both volume infusion and pericardiectomy. We conclude that pericardiectomy increases LA compliance and early LV filling rate and is accompanied by a relatively greater augmentation in conduit than reservoir function of the left atrium.

Effects of pericardiectomy on canine pulmonary blood volume during hypervolaemia

The aim was to determine the effect of the pericardium on the pulmonary blood volume response to intravascular volume loading. Changes in pulmonary lung volume were measured from radioactive counts over the lung during radionuclide ventriculography. Baseline measurements, and repeat measurements after infusion of 21 ml.kg-1 of the dog's own blood, were made both before and after a pericardiectomy. Ten closed chest, anaesthetised dogs were studied. Prior to and following pericardiectomy, volume loading produced equivalent and significant increases in left atrial, mean pulmonary artery, and right atrial pressures (all p less than 0.05). Before pericardiectomy, radionuclide lung counts increased from 1606(SEM 348) to 1870(402) with volume loading, corresponding to a 16% rise in lung counts from baseline (p less than 0.05). Following pericardiectomy, a similar volume load did not result in a significant rise in lung counts [1588(245) to 1697(255), 9%, p = 0.16], but was accompanied by an increase in left ventricular diastolic volume, from 39.7(6.6) to 58.7(6.4) ml, p less than 0.05, and a decrease in systemic vascular resistance index, from 122,600(14,600) to 86,600(10,000) dynes.s.cm-5 x kg, p less than 0.05. These data support the concept that removal of the pericardium is accompanied by reduced pulmonary blood volume overload in response to intravascular volume loading. The mechanism appears to be related to improved left ventricular diastolic filling, perhaps the result of diminished ventricular interaction, and to redistribution of excess intravascular volume from the pulmonary to the systemic circuit.

The effect of pericardiectomy on maximal oxygen consumption and maximal cardiac output in untrained dogs.

To test the hypothesis that the pericardium limits maximal oxygen consumption by limiting stroke volume and cardiac output, we studied 10 untrained dogs during submaximal and maximal exercise before and after pericardiectomy. Seven additional dogs were studied before and after a sham operation. All dogs were instrumented chronically with aortic and pulmonary artery catheters. Dogs were tested by running on a motor-driven treadmill, 4-6 times before and after pericardiectomy or sham operation. We measured cardiac output (dye dilution), heart rate, and arteriovenous oxygen difference. Oxygen consumption and stroke volume were calculated from these variables. After pericardiectomy, there were significant (P less than 0.01) increases in maximal oxygen consumption, maximal cardiac output, and maximal stroke volume. Maximal oxygen consumption decreased significantly in the sham group. There was no change in maximal heart rate following pericardiectomy, or in maximal cardiac output, heart rate, or stroke volume following sham operation. Both groups of dogs experienced similar significant decreases in hematocrit, arterial and venous oxygen contents, and arteriovenous oxygen difference. Neither pericardiectomy nor sham operation had any effect on oxygen consumption during submaximal exercise. However, the sham group had significant increases in cardiac output and heart rate during submaximal exercise, and the pericardiectomy group demonstrated a trend toward an increased cardiac output during submaximal exercise. These results support the hypothesis that the pericardium limits maximal oxygen consumption by limiting stroke volume and cardiac output during maximal exercise in untrained dogs. Further, these findings suggest that maximal oxygen consumption is limited by the oxygen transport capacity of the cardiovascular system, and not by the oxidative capacity of skeletal muscle in the untrained dog.

Effect of digitoxin on cardiac hypertrophy induced by pericardiectomy and exercise.

Removal of the pericardium in combination with a mild exercise programme of swimming resulted in a significant increase in heart weight and heart weight/body weight ratio of young rats. Heart weight/body weight ratios were 3.46+/-0.25 in the sedentary control animals, 4.16+/-0.26 in pericardiectomized animals swimming 2 h each day, and 4.60+/-0.22 in pericardiectomized animals swimming 6h/d. The effect of pericardiectomy on the development of cardiac hypertrophy is additive to that of mild exercise (2h/d) but not to prolonged exercise (6h/d). The administration of digitoxin significantly decreased the development of cardiac hypertrophy in pericardiectomized animals that were exercised for 2 h/d but not those exercised for 6 h/d. These findings further substantiate the physiological effect on the heart of the pericardium. The effects of pericardiectomy should be considered in experimental studies of cardiac hypertrophy and in clinical studies involving cardiac surgery.

Cardiac hypertrophy: synergistic effects of pericardiectomy and mild exercise in rats.

Removal of the pericardium in combination with a mild exercise program of swimming resulted in a significant increase in heart weight and heart weight/body weight ratio of young rats. Either exercise or pericardiectomy alone did not significantly alter these parameters as compared to the control group of rats. This finding further substantiates the pericardium's physiologic effect on the heart. The effects of pericardiectomy should be considered in experimental studies of cardiac hypertrophy and in clinical studies involving cardiac surgery.

Immediate effects of pericardiectomy

Immediate effects of pericardiectomy

THE SIGNIFICANCE OF THE PERICARDIUM IN RELATION TO SURGERY OF THE HEART

I. Introduction. II. History. III. Experiments and Comment. 1. The effect of mechanical trauma applied to the pericardium. 2. The effect of blood in the pericardial cavity. 3. The effect of hot salt solution applied to the heart and to the pericardium. 4. The effect of infection in the pericardial cavity. 5. The effect of tincture of iodin injected into the pericardial cavity. 6. The transplantation of fat into defects of the pericardium. 7. Heart tamponade. Report of two cases. 8. The effect of pericardiectomy. IV. Summary. I. INTRODUCTION Following any surgical procedure on the heart, important and sometimes serious sequelae may arise which involve the pericardium or which may be dependent on its presence. The most important of these sequelae are (1) a rapidly forming pericardial effusion which may lead to fatal tamponade, and (2) cardiopericardial adhesions which commonly follow the subsidence of the effusion. The significance of these