11/622. Reversible congestive heart failure caused by myocardial hibernation. Myocardial hibernation is reversible contractile dysfunction of cardiac myocytes caused by chronic ischemia. Animal studies and observations in human beings suggest that the term hibernation is a misnomer. Repetitive ischemic insult that does not produce necrosis results in functional and histologic tissue deterioration, which culminates in myocyte apoptosis. Revascularization of "hibernating" myocardium results in partial or complete recovery of function, depending upon the duration of ischemia and the severity of cellular degeneration. Improvement in global left ventricular function is proportional to the quantity of hibernating tissue that is revascularized, but this threshold quantity has not been determined with certainty. Diagnostic methods used to detect viable tissue within akinetic left ventricular segments depend upon the recognition of recruitable contractile function or the active concentration of a radioactive tracer. No diagnostic method has shown clear superiority. The most sensitive methods appear to be single-photon emission computed tomographic imaging after reinjection of thallium-201 at 24 hours and positron-emission tomographic imaging with 18F-fluorodeoxyglucose. The most specific diagnostic method appears to be measurement of dobutamine-stimulated contractile function, using either echocardiography or gated magnetic resonance imaging. We present a review of the pathophysiology, diagnosis, and treatment of myocardial hibernation, and include an illustrative case report involving a 57-year-old man with myocardial hibernation. ( info) |
12/622. Right ventricular myocardial bridge in a patient with pulmonary hypertension--a case report. Myocardial bridge is a not uncommon finding in routine diagnostic coronary angiography or pathological examination of the heart. It is almost always confined to the left ventricle and the left anterior descending coronary artery. This report describes a patient with chronic lung disease, severe left ventricular dysfunction, and pulmonary hypertension in whom coronary angiography revealed bridging of the right ventricular branch of the right coronary artery. ( info) |
13/622. Transient left ventricular failure following bilateral lung transplantation for pulmonary hypertension. BACKGROUND: Bilateral lung transplantation is an established therapy for end-stage pulmonary hypertension. Its early postoperative outcome may be biased by various complications resulting in unexpected deterioration of the patient in terms of hemodynamics and blood gases. methods: We have reviewed the early postoperative course of patients who underwent bilateral lung transplantation for pulmonary hypertension at our institution and analyzed all available data, especially hemodynamic measurements, echocardiographic documentation and therapeutical strategies, in those cases where cardiac dysfunction was found to be responsible for clinical deterioration. RESULTS: Three out of 20 lung transplant recipients operated for pulmonary hypertension experienced severe respiratory insufficiency accompanied by hemodynamic decompensation during the first days after surgery. Clinical and laboratory findings together with results of echocardiography and pulmonary artery catheterism helped establish the diagnosis of left ventricular failure. This proved to be transitory, but the response to therapy (inotropic drugs, afterload reduction and eventually prostaglandins) was very variable. Adequately treated, this complication did not preclude the outcome of transplantation by itself. CONCLUSION: Left ventricular failure is a possible complication after lung transplantation for pulmonary hypertension. echocardiography and pulmonary artery catheterism may be useful adjuvant diagnostic tools, beside routine physical examination, chest X-ray, and laboratory analysis. Therapy of this complication must be adapted individually and may be complex. ( info) |
14/622. Reversible catecholamine-induced cardiomyopathy in a heart transplant candidate without persistent or paroxysmal hypertension. BACKGROUND: Both dilated and hypertrophic cardiomyopathy have been reported in patients with pheochromocytoma, who were almost always hypertensive. The outcome frequently has been fatal, yet cardiac dysfunction can be reversible after medical or surgical therapy for the pheochromocytoma. methods: We report the case of a patient with dilated cardiomyopathy without persistent or paroxysmal hypertension, who was found to have a pheochromocytoma during initial medical evaluation. RESULTS: The identification and treatment of the pheochromocytoma led to significant improvement in cardiac function and cardiac transplantation was avoided. CONCLUSIONS: This case illustrates some unusual features in pheochromocytoma-induced cardiomyopathy: (1) absence of persistent or paroxysmal hypertension, (2) initial presentation with acute myocardial infarction and normal coronary arteries, and (3) recurrent episodes of nonsustained ventricular tachycardia. ( info) |
15/622. Thrombotic occlusion of the main stem of the left coronary artery in a neonate. Thrombotic coronary arterial occlusion, and myocardial infarction, are rare in the newborn. We report such a happening presenting shortly after birth with cardiogenic shock, no left ventricular output and a systemic circulation dependent on flow from a patent arterial duct. ( info) |
| coffin-lowry syndrome is an X-linked recessive syndrome of mental retardation, characteristic facies and skeletal anomalies. In one patient with the syndrome, we observed early recurrent episodes of congestive heart failure with intercurrent normalization and the late development of mitral insufficiency due to annular dilation and congenital abnormalities of the valve apparatus. This unusual course of cardiac involvement, the non-adaptation of the left ventricular contractility to the aggravation of the mitral insufficiency and the postoperative persistence of the ventricular dysfunction, underline the possible role of an associated primary myocardial disease. This clinical observation demonstrates clearly that a mitral valve malformation can occur in patients with the syndrome, but also the role of a dilated cardiomyopathy, which can be secondary to the mitral regurgitation, but is more likely a myocardial disorder occurring as part of the syndrome. ( info) |
17/622. Effects of extracorporeal shock wave lithotripsy on tiered therapy implantable cardioverter defibrillators. The effects of extracorporeal shock wave lithotripsy (ESWL) were tested on four advanced generation implantable cardioverter-defibrillators (ICDs) in vitro and in vivo in two patients. During in vitro testing, advancement of nonsustained episode counters occurred in one device, and a set screw and power source cell loosened in another, which was connected to an external power source. No arrhythmias occurred during in vivo procedures, but programmed parameters were reset and elective replacement indicated after one procedure. ESWL can be performed safely in selected patients with ICDs, but testing should be performed afterwards to confirm satisfactory function and component continuity. ( info) |
18/622. Reversible biventricular dysfunction secondary to ischemia in a patient with acute airway obstruction: a case report and review of the literature on reversible causes of acute ventricular dysfunction. Reversible causes of acute myocardial dysfunction are important for clinicians to recognize. Reversible biventricular dysfunction secondary to myocardial ischemia is presented in a patient with acute upper airway obstruction. The differential diagnosis of reversible acute myocardial dysfunction is reviewed. ( info) |
19/622. Inappropriate implantable defibrillator discharge caused by a retained pacemaker lead fragment. INTRODUCTION: Inappropriate discharge is still a major issue of implantable cardioverter defibrillator therapy. The diagnostic options of modern devices facilitate classification of the underlying abnormality. methods AND RESULTS: A 65-year-old woman with depressed left ventricular performance received spurious shocks from an ICD, implanted for ventricular tachycardia. A lead fragment of an explanted VVI pacemaker system could be identified as cause of erroneous ventricular fibrillation detection by the ICD. The electrical noise caused by interaction between the lead remnant and the ICD lead was detectable even on the surface ECG. CONCLUSION: Based on our findings, removal of fragmented lead material should be considered prior to ICD implantation, to avoid potentially adverse and harmful interactions with ICD systems. ( info) |
20/622. Pulmonary stenosis and severe biventricular dysfunction: improvement following percutaneous valvuloplasty. A 15-year-old boy with severe pulmonary stenosis associated with severe right and left ventricular systolic dysfunction is reported. After successful percutaneous pulmonary valvuloplasty, there was an initial and early improvement in right ventricular (RV) function, followed by a delayed and more gradual improvement in left ventricular (LV) function. At long-term follow up, both RV and LV systolic functions were nearly normalized. Several mechanisms may be implicated, including ventricular interdependence, geometric factors, altered compliance and intrinsic alteration in the LV muscle. A delayed, but sustained, improvement in LV systolic function following relief of RV pressure overload suggests that the latter mechanism must have played an important role in the genesis of the LV dysfunction. Pulmonary stenosis associated with severe biventricular dysfunction may be treated primarily by percutaneous pulmonary balloon valvuloplasty with near-total recovery of the ventricular function. ( info) |