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Biomedical subjects

Igor D Gregoric

Publications and source records attributed to Igor D Gregoric.

At least 19 recordsLinked to original sources

Mycotic pseudo-aneurysm of the ascending thoracic aorta after cardiac transplantation.

A large mycotic pseudo-aneurysm of the ascending thoracic aorta was found in a patient with empyema and infectious mediastinitis after an orthotopic heart transplant procedure. The patient underwent surgical resection of the pseudo-aneurysm with patch aortoplasty and was treated with appropriate long-term antibiotic therapy. The patient continues to do well 3 months after surgery. Early surgical intervention combined with pre-operative and prolonged post-operative antibiotic therapy and close follow-up is essential in these patients.

Adult↗

Initial experience with non-thoracic, extraperitoneal, off-pump insertion of the Jarvik 2000 Heart in patients with previous median sternotomy.

BACKGROUND: Successful implantation of left ventricular assist devices (LVADs) in patients with previous median sternotomy remains challenging. METHODS: Seven patients underwent implantation of a Jarvik 2000 Heart by an extrathoracic, extraperitoneal, sub-costal surgical approach, which allows easy exposure of the diaphragmatic surface of the heart and the supraceliac aorta. All patients were at very high risk and were receiving high doses of inotropic agents to maintain their cardiac function. All had undergone prior median sternotomy. We compared data for blood loss and intensive care unit (ICU) stay with those of 15 patients in whom the HeartMate I vented electric LVAD was placed through a re-do sternotomy incision. RESULTS: All 7 patients survived the surgical procedure for implantation of the Jarvik 2000. All 7 patients were rapidly rehabilitated and had a short stay in the ICU (mean 3.3 days, range 1 to 8 days), as compared with the re-do HeartMate patients (mean 10.3 days, range 3 to 33 days) (p = 0.005). The average 12-hour blood loss was 635 ml in the Jarvik patients compared with 2,405 ml in the re-do HeartMate patients (p = 0.028). The cardiac index improved significantly in all Jarvik patients. CONCLUSIONS: The extrathoracic, extraperitoneal, sub-costal surgical approach is less invasive than a median sternotomy and allows the Jarvik 2000 to be implanted quickly and without cardiopulmonary bypass (CPB). By avoiding CPB and an extensive mediastinal dissection, bleeding is decreased in these hypocoagulable patients with compromised end-organ function. The decreased operative morbidity and mortality associated with this technique may allow consideration of the Jarvik 2000 Heart for safe and effective implantation in home-bound New York Heart Association (NYHA) Class III and IV patients.

Blood Loss, Surgical↗

Myocardial thievery: the coronary-subclavian steal syndrome.

Coronary-subclavian steal syndrome entails the reversal of blood flow in a previously constructed internal mammary artery coronary conduit, which produces myocardial ischemia. The most frequent cause of the syndrome is atherosclerotic disease in the ipsilateral, proximal subclavian artery. Although coronary-subclavian steal was initially reported to be rare, the increasing documentation of this phenomenon and its potentially catastrophic consequences in recent series suggests that the incidence of the problem has been underreported and that its clinical impact has been underestimated. We review the causes and background of coronary-subclavian steal; methods of preventing, diagnosing, and treating it; and the potential influence of various treatment regimens on long-term survival and the likelihood of late adverse events in patients with coronary-subclavian steal syndrome.

Anticoagulants↗

Is native aortic valve commissural fusion in patients with long-term left ventricular assist devices associated with clinically important aortic insufficiency?

BACKGROUND: Long-term left ventricular assist device (LVAD) support diminishes flow through the native aortic valve and decreases valve motion. This may cause aortic valve commissural fusion. The clinical importance of such fusion is not well understood. METHODS: Thirty-three consecutive patients receiving long-term LVAD support were followed up until transplantation or death. In each case, the native aortic valve was examined pathologically for commissural fusion. Pathology findings were correlated with hemodynamic performance as assessed by both LVAD pump flow and echocardiography. RESULTS: Seventeen of the 33 patients had some degree of native aortic valve commissural fusion. Four patients had fusion at 2 commissures; of these, 2 had clinically significant native valve aortic insufficiency (2+ or greater), and 1 exhibited trace insufficiency of the native aortic valve. Thirteen patients had fusion at only 1 aortic commissure; of these, 2 had clinically significant aortic insufficiency (2+ or greater), and 3 had trace or mild (1+) insufficiency of native aortic valve. Two of the 4 patients with fusion at 2 commissures required increased LVAD support of >3 liters/min/cm2. No patient with fusion of only 1 commissure required increased LVAD support. Three patients with no commissural fusion of the aortic valve required increased LVAD support secondary to sepsis. CONCLUSIONS: Commissural fusion of the native aortic valve occurs in a significant number of patients receiving long-term LVAD support and can necessitate increased levels of LVAD support. Recognition of this phenomenon may allow development of strategies to minimize commissural fusion and extend LVAD pump life.

Adult↗

Hemodynamics and patient safety during pump-off studies of an axial-flow left ventricular assist device.

BACKGROUND: Axial-flow left ventricular assist devices (LVADs), when inactivated, may result in regurgitant blood flow. We assessed the effects of regurgitant pump flow with the intraventricular Jarvik 2000 Heart LVAD (Jarvik Heart, Inc., New York, NY) on hemodynamics and patient safety under pump-off conditions. METHODS: Thirty patients being supported by a Jarvik 2000 as a bridge to heart transplantation underwent pump-off studies. Hemodynamics, vital signs and cognitive function were monitored; Doppler echocardiographic studies were done with the pump turned off for 5 minutes if tolerated. Regurgitant flow was assessed in terms of the difference between left ventricular and right ventricular outflow tract cardiac output (LVOT CO - RVOT CO). RESULTS: During pump-off periods, the mean regurgitant flow was 0.42 +/- 0.41 liter/min, and the mean arterial blood pressure was 63.1 +/- 11.6 mm Hg. There was no regurgitant flow when the pump was on. Three patients did not tolerate the pump being off for periods of 5 minutes; in these tests, the mean regurgitant flow rate was 0.54 +/- 0.50 liter/min, the mean arterial blood pressure was 52.8 +/- 9.8 mm Hg, and the mean pump-off time was 3.1 +/- 1.1 minutes. All patients remained conscious during the pump-off period, and none showed lasting adverse effects. CONCLUSIONS: Our findings suggest that patients being supported with the axial-flow Jarvik 2000 Heart LVAD can generally tolerate pump-off times of 5 minutes.

Adult↗

Fatal pulmonary microthrombi during surgical therapy for end-stage heart failure: possible association with antifibrinolytic therapy.

BACKGROUND: Maintaining hemostasis in patients with end-stage heart failure undergoing cardiac surgery is always challenging. These patients have chronic hepatic insufficiency, resulting in derangement of coagulation. In addition, they are commonly receiving both systemic anticoagulation (warfarin or heparin) and antiplatelet therapy. The introduction of antifibrinolytics has had a significant effect on postoperative coagulopathy. We report fatal pulmonary microthrombi in patients receiving antifibrinolytics who developed suprasystemic pulmonary artery pressures and right heart failure that was impossible to overcome despite insertion of a right ventricular assist device. METHODS: We reviewed the surgical procedure and autopsy reports to identify patients with high pulmonary artery pressures caused by pulmonary microthrombi after a cardiac surgical procedure for end-stage heart failure. Patient demographics and preoperative, intraoperative, and postoperative variables were collected from a retrospective review of the patients' medical records. RESULTS: We identified 9 patients (7 men and 2 women; mean age, 45 +/- 16 years) who died of pulmonary microthrombi after cardiac surgery between January 1997 and January 2004. Surgical procedures included 5 left ventricular assist device implantations, 2 heart transplantations, and 2 left ventricular reconstructions with mitral valve repair or replacement. Eight patients received aprotinin, and 1 patient received epsilon-aminocaproic acid immediately before and during cardiopulmonary bypass. All patients had severe suprasystemic pulmonary artery pressures after protamine administration for heparin reversal, a complication that proved fatal in all cases. Intraoperative wedge biopsy of the lungs revealed multiple microthrombi within capillaries and in the small- and medium-sized pulmonary arterioles. CONCLUSION: We report 9 cases for which fatal pulmonary microthrombi might be associated with the use of prophylactic antifibrinolytic therapy. Mortally ill patients with multiorgan failure who are receiving systemic anticoagulation and undergoing surgical procedures require careful perioperative monitoring to identify potential hazards. Anticoagulation and antifibrinolytic therapy protocols may require adjustment in such patients.

Adult↗

QTc interval prolongation predicts postoperative mortality in heart failure patients undergoing surgical revascularization.

QTc interval prolongation is associated with increased mortality rates in patients with advanced heart failure. We investigated the predictive value of prolonged QTc interval in 567 patients with heart failure who were undergoing coronary artery bypass graft surgery The patients were in New York Heart Association class III or IV, with left ventricular ejection fractions of 0.40 or less. Before surgery, the QT interval duration was measured in leads II and V4 of the standard electrocardiogram and corrected by use of the Bazett formula. The QTc interval was prolonged (>440 msec) in 243 patients (43%) and normal in 324 (57%). The 2 study groups--prolonged QTc versus normal QTc--did not differ in terms of age (62 +/- 11 years vs 64 +/- 10 years, P=0.65), sex (80% male vs 76% male, P=0.31), ejection fraction (0.29 +/- 0.08 vs 0.29 +/- 0.09, P=0.72), hypertension (82% vs 78%, P=0.34), or diabetes (11% vs 7%, P=0.10). Within 1 month after coronary artery bypass grafting, 22 of 243 patients (9.1%) in the prolonged QTc group died, compared with 5 of 324 in the normal QTc group (1.5%) (P=0.0001). QTc interval prolongation was the only independent predictor of postoperative mortality on multivariate analysis (P=0.002). We conclude that patients with heart failure and preoperative QTc interval prolongation have increased mortality rates after coronary artery bypass grafting.

Coronary Artery Bypass↗

Clinical experience with the TandemHeart percutaneous ventricular assist device.

The TandemHeart percutaneous ventricular assist device can be used to support patients in cardiogenic shock (until cardiac recovery occurs or as a bridge to definitive therapy) or as a temporary application during high-risk coronary interventions. The TandemHeart is a left atrial-to-femoral artery bypass system comprising a transseptal cannula, arterial cannulae, and a centrifugal blood pump. The pump can deliver flow rates up to 4.0 L/min at a maximum speed of 7500 rpm. From May 2003 through May 2005, the TandemHeart was used to support 18 patients (11 in cardiogenic shock and 7 undergoing high-risk percutaneous transluminal coronary angioplasty). The patients in cardiogenic shock were supported for a mean of 88.8 +/- 74.3 hours (range, 4-264 hr) at a mean pump flow rate of 2.87 +/- 0.56 L/min (range, 1.8-3.5 L/min). The mean cardiac index improved from 1.57 +/- 0.31 L/min/m2 before support to 2.60 +/- 0.34 L/min/m2 during support. The mean duration of support for the high-risk percutaneous transluminal coronary angioplasty patients was 5.5 +/- 8.3 hours (range, 1-24 hr). The mean flow rate was 2.42 +/- 0.55 L/min (range, 1.5-3.0 L/ min). The overall 30-day survival rate was 61%. In our experience, the TandemHeart device was easy to insert and provided a means either to cardiac recovery or to continued support with an implantable left ventricular assist device.

Aged↗

Saphenous vein graft flow during left ventricular assistance with an axial-flow pump.

The effects of continuous-flow support on bypass graft flow have not been quantified clinically. Continuous-flow left ventricular assist devices unload the left ventricle throughout the cardiac cycle, which narrows pulse pressure and converts passive left ventricular filling during diastole to active flow throughout the cardiac cycle. We report the case of a 63-year-old man with severe congestive heart failure who underwent coronary artery bypass grafting and was supported with an axial-flow pump. In this patient, saphenous vein graft flow during left ventricular assistance provided adequate coronary perfusion.

Coronary Artery Bypass↗

Endovascular repair of a ruptured descending thoracic aortic aneurysm.

Endovascular aneurysm repair has considerable potential advantages over the surgical approach as a treatment for thoracic aortic rupture, in part because open surgical repair of ruptured thoracic aortic aneurysms is associated with high mortality and morbidity rates. We describe the successful endovascular deployment of stent-grafts to repair a contained rupture of a descending thoracic aortic aneurysm in an 86-year-old man whose comorbidities prohibited surgery. Two months after the procedure, magnetic resonance angiography showed a patent stent-graft, a patent left subclavian artery, and complete exclusion of the aneurysm.

Aged, 80 and over↗

Use of a percutaneous ventricular assist device for treatment of cardiogenic shock due to critical aortic stenosis.

We present the case of a 72-year-old woman who was transferred to our institution in cardiogenic shock and with multiple-organ failure, due to critical aortic stenosis. She was considered too high-risk to undergo aortic valve replacement. A TandemHeart percutaneous ventricular assist device was used to stabilize the patient's condition before surgery, and she subsequently underwent successful aortic valve replacement. To our knowledge, this is the 1st report in the literature of this particular application of the TandemHeart device.

Aged↗

First use of the TandemHeart percutaneous left ventricular assist device as a short-term bridge to cardiac transplantation.

Advanced heart failure may be refractory despite aggressive support with inotropic agents and intra-aortic balloon pumping. Implantable left ventricular assist devices are increasingly being used as bridges to cardiac transplantation or as destination therapy because of the limited availability of donor organs. We report the 1st use of the TandemHeart percutaneous ventricular assist device as a short-term bridge to cardiac transplantation.

Cardiomyopathies↗

Orthotopic retransplantation in heterotopic transplant recipients: 3 case reports.

We report 3 patients who initially underwent heterotopic transplantation due to a size mismatch but then later underwent orthotopic retransplantation because of heart failure. In each case, the heterotopic graft was left in place, the native heart was removed, and the new allograft was placed orthotopically. This technique resulted in reduced postoperative morbidity and excellent long-term outcomes.

Adult↗

Concomitant brachiocephalic and coronary artery disease: outcome and decision analysis.

BACKGROUND: In patients with coronary artery disease, concomitant brachiocephalic disease may affect outcome and influence decision making regarding operative staging, technique, and choice of conduit. METHODS: Eighty consecutive patients (mean age, 59.3 years; 60.0% male) with concomitant brachiocephalic and coronary artery disease were identified either before (group A, n = 48) or after (group B, n = 32) coronary artery bypass grafting. Patients who had symptomatic brachiocephalic and coronary artery disease before surgery underwent concomitant brachiocephalic reconstruction and coronary artery bypass grafting using either all-vein coronary conduits (n = 41) or vein-and-internal mammary artery conduits (n = 7). Patients who had coronary-subclavian steal syndrome after coronary artery bypass (group B, n = 32) underwent either surgical (n = 5) or endovascular (n = 27) brachiocephalic reconstruction only. RESULTS: All patients were asymptomatic after intervention. Operative mortality was 4.2% for group A and 3.1% for group B. The perioperative stroke rate was 2.1% for group A and 0% for group B. Actuarial 10-year freedom from specific events for group A was as follows: death 59.9 +/- 12.8%, brachiocephalic restenosis 100%, coronary-subclavian steal syndrome 100%, myocardial infarction 83.5 +/- 10.5%, stroke 82.1 +/- 9.9%, redo coronary artery bypass grafting 95.8 +/- 4.1%, other vascular operation 82.2 +/- 8.9%, and adverse cardiac outcome (death, redo coronary artery bypass grafting, or myocardial infarction) 52.9% +/- 13.2% (for patients with all-vein conduits) or 100% (for patients with vein-and-internal mammary artery conduits). At midterm follow-up (mean, 2.92 years), both the surgical and the endovascular treatment subgroups of group B had 100% brachiocephalic patency. CONCLUSIONS: Long-term results in a limited population support continued evaluation of concomitant brachiocephalic reconstruction and coronary artery bypass grafting with use of the internal mammary artery conduit in an attempt to improve late survival in patients with concomitant disease. The excellent midterm brachiocephalic patency after either surgical or endovascular treatment of patients with coronary-subclavian steal syndrome supports continued evaluation of both methods.

Adult↗