Goor Da

Review of echocardiographically diagnosed right heart entrapment of pulmonary emboli-in-transit with emphasis on management

2DE permits detection of thromboemboli transiently entrapped in the right heart chambers while en route to the pulmonary arteries. Review of the 49 cases recorded to date reveals that the supple elongated clot produces a 2DE picture--a mass of changing configuration and striking mobility--that is highly characteristic. Since emboli that become entrapped are large, when managed by medical measures alone they have an attendant mortality rate of 50%, usually soon after 2DE diagnosis, upon completion of pulmonary embolization. Death occurred in 8 of 16 patients treated with anticoagulants, thrombolytic agents, or antiaggregants and in 6 of 13 who received supportive measures only. Of 20 patients referred for surgery (cardiotomy and, in 17, pulmonary embolectomy), only three died, two of them failures of preceding anticoagulant treatment. These data indicate that thromboemboli entrapped in the right heart chambers are best handled as a surgical emergency.

Platelet protection by low-dose aprotinin in cardiopulmonary bypass: Electron microscopic study

To evaluate the effect of low-dose aprotinin during cardiopulmonary bypass on platelet function and clinical hemostasis, 30 patients undergoing various cardiopulmonary bypass procedures employing bubble oxygenators were randomized to receive either low-dose aprotinin (2 x 10(6) KIU in the cardiopulmonary bypass priming solution, 15 patients [group A]) or placebo (15 patients [group B]). Blood samples were collected before and after cardiopulmonary bypass to assess platelet count and aggregation on extracellular matrix, which was studied by a scanning electron microscope. On a scale of 1 to 4 preoperative mean platelet aggregation grades were similar in both groups (3.8 +/- 0.5 and 3.5 +/- 0.5 for groups A and B, respectively). Postoperatively, platelet aggregation on extracellular matrix decreased slightly in group A (2.8 +/- 1.3; p < 0.01) and significantly in group B (1.3 +/- 0.5; p < 0.001). Eleven of the 15 patients in group A remained in aggregation grade 3 or 4 compared with none of the group B patients. Platelet count was similar in both groups preoperatively and postoperatively. Total 24-hour postoperative bleeding and blood requirement were lower in the aprotinin group (487 +/- 121 mL and 2.3 +/- 1.0 units) than in the placebo group (752 +/- 404 mL and 6.8 +/- 5.1 units; p < 0.01). These results show that the use of low-dose aprotinin during cardiopulmonary bypass provides improved postoperative hemostasis, which might be related to the protection of the platelet aggregating capacity.

Changes in systemic vascular resistance detected by the arterial resistometer: preliminary report of a new method tested during percutaneous transluminal coronary angioplasty.

A recently developed apparatus provides on-line continuous monitoring of systemic vascular resistance (SVR) by means of simple computer analysis of the peripheral arterial waveform. The fundamental equation of this method is Ri = P/(dP/dt), where dP/dt is the peak dP/dt of the peripheral arterial waveform, P is the pressure at time of peak dP/dt, and Ri is a resistance index that bears a direct relation to SVR. Eleven patients undergoing percutaneous transluminal coronary angioplasty (PTCA) were studied to evaluate the changes in SVR associated with myocardial ischemia (angina detection). There were 49 balloon inflations, all of which were associated with an increase in Ri (from 38.4 +/- 12 to 81.2 +/- 36 X 10(-3) sec; p less than .01) and a decrease in dP/dt (from 2076 +/- 257 to 1327 +/- 326 mm Hg/sec; p less than .01). In 42 of the balloon inflations these changes were associated with electrocardiographic ST-T changes and in 23 it was also associated with anginal pain. When angina was present, a further increase in Ri (to 97.5 +/- 43 X 10(-3) sec; p less than .01) and a decrease in dP/dt (to 1218 +/- 338 mm Hg/sec; p less than .01) was observed. It was found that myocardial ischemia is associated with an increase in the resistance index and a decrease in dP/dt and can be detected by the resistometer.

Dissecting Aneurysms of the Thoracic Aorta: A Review of 52 Cases with Consideration of Factors Influencing Prognosis

arlier reviews of dissecting aneurysm of the thoracic aorta have indicated the nearly fatal prognosis attached to this disease E [ Z , 7, 9, 11, 131. Recently, a more aggressive approach has been suggested in the treatment of dissecting aneurysm [3, 121. Although surgery seems to have improved the survival rate [ l , 5 , 8 ] , several problems remain to be solved. Of most concern is the frequent rapid evolution of the disease. Numerous patients do not reach the hospital, while others succumb in the course of diagnostic studies or sometimes during thoracotomy. Our purpose here is to review 52 cases of dissecting aneurysm of the thoracic aorta, to delineate the natural history of the disease, and to define the factors influencing the prognosis, especially in relation to management. This series is, in this respect, of interest since half of the patients were treated surgically.

Correction of tetrad of fallot with reduced incidence of right bundle branch block

In 20 patients who underwent a modified surgical repair of tetrad of Fallot complete right bundle branch block developed in only 8 (40 percent). Standard and intraoperative conduction studies indicated that in these patients the right bundle branch block was due to injury of the right bundle branch near the ventricular septal defect (proximal right bundle branch block). The modified operative technique is aimed at minimizing the injury to the right ventricle and it includes a significantly shorter than usual ventriculotomy incision and avoidance of the septal (moderator) band during infundibulectomy. Intra- and postoperative hemodynamic studies of these patients revealed that relief of the right ventricular outflow obstruction was optimal.

Atrial septal defect and constrictive Pericarditis

Abstract A case of atrial septal defect complicated by constrictive pericarditis is described. Phonocardiograms showed wide and “true” fixed splitting of the second sound. It is stressed that the clinical diagnosis of atrial septal defect is not hindered by the presence of constrictive pericarditis, even though the presence of constrictive pericarditis may be confused with congestive heart failure, with or without tricuspid insufficiency.

Irradiation of Fresh Whole Blood for Prevention of Transfusion‐Associated Graft‐versus‐Host Disease Does Not Impair Platelet Function and Clinical Hemostasis after Open Heart Surgery

Since our previous studies suggested that the transfusion of 1 unit fresh whole blood (FWB) after cardiopulmonary bypass (CPB) using a bubble oxygenator may provide hemostatic benefit equivalent to 8–10 units of platelet concentrates, we have routinely used FWB at the termination of CPB. Two patients who received FWB and developed transfusion‐associated graft‐versus‐host disease (TA‐GVHD) prompted us to investigate the effect of irradiation of FWB on platelet and clinical hemostasis. Twenty‐four patients were randomized to receive either 1 unit FWB (12 patients), or 1 unit irradiated FWB (IrFWB, 1,500 cGy, 12 patients) after CPB. Platelet aggregation on extracellular matrix, studied by a scanning electron microscope and graded from 1 to 4 (from poor to excellent aggregation), was similar in both groups preoperatively [3.3±0.9 (FWB) and 3.5±0.5 (Ir FWB)], and at the end of CPB [1.8±1.2 (FWB) and 1.9±0.9 (IrFWB)]. Platelet aggregation was similar after transfusion of FWB (3.0±1.0) and after IrFWB (3.2±0.8), as was the increase in platelet count. Twenty‐four hours total postoperative bleeding was similar (560±420 and 523±236 ml for FWB and IrFWB, respectively). We conclude that irradiation of FWB for prevention of TA‐GVHD does not impair platelet aggregating capacity, and can be used when blood is donated by the patients next of kin.

Is Transfusion of Fresh Plasma After Cardiac Operations Indicated

Patients undergoing cardiac operations constitute the majority of recipients of fresh frozen plasma. In most centers the reason for transfusing fresh frozen plasma is to replace clotting factors. However, the decrease of clotting factors during cardiopulmonary bypass is not sufficient in most patients to cause abnormal bleeding. One of the major causes of nonsurgical bleeding after cardiac operations is acquired platelet dysfunction, which can be corrected by transfusion of 1 unit of fresh whole blood. Because plasmatic factors in fresh whole blood may be responsible for this improvement, a study was designated to evaluate the effect of transfusing fresh plasma on platelet function after cardiac operations. Forty patients undergoing cardiopulmonary bypass were randomized to receive either fresh plasma or the fresh packed cell fraction. Administration of packed cells increased platelet number (118 +/- 8.5 to 154 +/- 7.6 x 10(9)/L, p less than 0.05), shortened bleeding time (7.57 +/- 0.4 to 4.0 +/- 0.3 minutes, p less than 0.05), and improved platelet aggregation in response to collagen and epinephrine (32% +/- 4.7% to 50% +/- 5.6% and 37% +/- 5.8% to 50% +/- 5.8%, respectively, p less than 0.05). Fresh plasma, however, neither increased platelet number nor improved bleeding time or platelet aggregation. Each group later received the remainder of the blood unit, with similar results. The results suggest that improvement of platelet function in patients receiving fresh whole blood after cardiac operations is not related to plasmatic factors. Therefore the massive use of fresh frozen plasma in patients after cardiopulmonary bypass should be reconsidered.

The Hemostatic Effect of Transfusing Fresh Whole Blood Versus Platelet Concentrates After Cardiac Operations

The major cause of nonsurgical bleeding after cardiopulmonary bypass is delayed recovery of platelet count and function. Recovery of platelet count and function was compared in 27 patients who were randomized preoperatively to receive after cardiopulmonary bypass either 1 unit of fresh whole blood (15 patients) or 10 units of platelet concentrates (12 patients). Platelet count, bleeding time, platelet aggregation (adenosine diphosphate, collagen, epinephrine, and ristocetin) and platelet thromboxane formation were abnormal after cardiopulmonary bypass in all the patients. The increase of platelet count after 1 unit of fresh whole blood (from 115 +/- 32 X 10(9)/L to 148.5 +/- 36 X 10(9)/L) was similar to that achieved by 4 units of platelets (from 140 +/- 61 X 10(9)/L to 171 +/- 60 X 10(9)/L). The increase was doubled after 10 platelet units (from 140 +/- 61 X 10(9)/L to 209 +/- 55 X 10(9)/L). Bleeding time returned to normal values after fresh whole blood or after 8 platelet units. However, platelet thromboxane formation was higher after 1 unit of fresh whole blood than after 10 platelet units (95 +/- 25 versus 46 +/- 35 ng/ml, p less than 0.05), as was platelet aggregation response to collagen and epinephrine. The 24-hour blood loss was smaller in the fresh whole blood group (560 +/- 420 ml versus 770 +/- 360 ml), although the difference was not statistically significant. The results suggest that the hemostatic effect of 1 unit fresh whole blood after cardiopulmonary bypass is at least equal, if not superior, to the effect of 10 units of platelets.

Inaccuracy of Radial Artery Pressure Measurement After Cardiac Operations

The phenomenon of a pressure gradient between central and radial arteries was evaluated in 48 patients immediately after coronary artery bypass operations. All were in stable hemodynamic condition, none receiving catecholamine support. In eight patients (Group A) mean femoral pressure was significantly higher than mean radial pressure (range 10 to 30 mm Hg). In the remaining 40 (Group B) radial and femoral pressures were equal. Mean cardiac index (thermodilution) was 3.3 +/- 0.68 versus 2.1 +/- 0.4 L/min/m2, systemic vascular resistance 1,181 +/- 218.4 versus 2,049 +/- 501 dynes/sec/cm-5, toe temperature 23.8 degrees +/- 1.2 degrees C versus 24.02 degrees +/- 0.9 degrees C, core temperature 33.9 degrees +/- 0.5 degrees C versus 34.1 degrees +/- 0.6 degrees C, mixed venous oxygen saturation 78% +/- 3% versus 62% +/- 5%, and peak radial dP/dt 1,485 +/- 366 versus 2,028 +/- 392 in Groups A and B, respectively. These data indicate, first, that the low radial pressures measured in Group A patients did not represent the true central aortic pressures; that is, they were false. Second, these low pressures had nothing to do with compromised cardiac function; rather, they were due to peripheral constriction and volume factors and also probably to proximal shunting. It is therefore recommended that while the chest is still open, if a discrepancy exists between a low radial artery pressure, a high palpable aortic pressure, and a satisfactory cardiac contraction, a femoral cannula for pressure measurement should be inserted. Treatment is by blood infusion until the femoral-radial gradient has been abolished.