Alan Shah

Protruding aortic arch atheromas: risk of stroke during heart surgery with and without aortic arch endarterectomy.

BACKGROUND Stroke occurs in 1% to 7% of heart surgery. Aortic arch atherosclerosis is a risk factor for intraoperative stroke, and endarterectomy has been proposed to prevent stroke during heart surgery in patients with arch atheromas. METHODS AND RESULTS Intraoperative transesophageal echocardiography was performed in 3404 patients undergoing heart surgery between 1990 and 1996. Use of transesophageal echocardiography was unselected and based on equipment availability. Aortic arch atheromas (>/=5 mm, or mobile) were seen in 268 (8%) patients. They were evaluated for intraoperative stroke (confirmed by a neurologist and cerebral infarction on computed tomography or magnetic resonance imaging). Arch endarterectomy was performed in 43 patients as an adjunct to their cardiac procedure in an attempt to prevent intraoperative stroke. The intraoperative stroke rate in all 268 patients with atheromas was high (15.3%). On univariate analysis, age, previous stroke, and arch endarterectomy were significantly associated with intraoperative stroke. On multivariate analysis, age (odds ratio 3.9, P =.01) and arch endarterectomy (odds ratio 3.6, P =.001) were independently predictive of intraoperative stroke. Mortality rate in all 268 patients was high (14.9%). These patients with atheromas also had a long recovery room, intensive care unit, and total hospital length of stay (48 days). CONCLUSIONS Patients with protruding aortic arch atheromas are at high risk for intraoperative stroke, significant and multiple morbidity, prolonged hospital stay, and death resulting from heart surgery. Aortic arch endarterectomy is strongly associated with intraoperative stroke; its use should be carefully considered in light of these results.

Amyloid and nonfibrillar deposits in mice transgenic for wild-type human transthyretin: a possible model for senile systemic amyloidosis.

The human serum protein transthyretin (TTR) is highly fibrillogenic in vitro and is the fibril precursor in both autosomal dominant (familial amyloidotic polyneuropathy [FAP] and familial amyloidotic cardiomyopathy [FAC]) and sporadic (senile systemic amyloidosis [SSA]) forms of human cardiac amyloidosis. We have produced mouse strains transgenic for either wild-type or mutant (TTRLeu55Pro) human TTR genes. Eighty-four percent of C57Bl/6xDBA/2 mice older than 18 months, transgenic for the wild-type human TTR gene, develop TTR deposits that occur primarily in heart and kidney. In most of the animals, the deposits are nonfibrillar and non-Congophilic, but 20% of animals older than 18 months that bear the transgene have human TTR cardiac amyloid deposits identical to the lesions seen in SSA. Amino terminal amino acid sequence analysis and mass spectrometry of the major component extracted from amyloid and nonamyloid deposits revealed that both were intact human TTR monomers with no evidence of proteolysis or codeposition of murine TTR. This is the first instance in which the proteins from amyloid and nonfibrillar deposits in the same or syngeneic animals have been shown to be identical by sequence analysis. It is also the first time in any form of amyloidosis that nonfibrillar deposits have been shown to systematically occur temporally before the appearance of fibrils derived from the same precursor in the same tissues. These findings suggest, but do not prove, that the nonamyloid deposits represent a precursor of the fibril. The differences in the ultrastructure and binding properties of the deposits, despite the identical sizes and amino terminal amino acid sequences of the TTR and the dissociation of deposition and fibril formation, provide evidence that in vivo factors, perhaps associated with aging, impact on both systemic precursor deposition and amyloid fibril formation.

Relation of Clinical, Echocardiographic and Electrocardiographic Features of Cardiac Amyloidosis to the Presence of the Transthyretin V122I Allele in Older African-American Men

Previous studies have shown that 3% to 4% of African Americans carry an amyloidogenic allele of the human serum protein transthyretin (TTR V122I). The allele appears to have an absolute anatomic risk for cardiac amyloid deposition after 65 years of age. In this study, a case-control comparison was performed of clinical, echocardiographic, and electrocardiographic characteristics of 23 age at risk carriers of the amyloidogenic allele and 46 age-, gender-, and ethnically matched noncarriers being evaluated for cardiac disease using standard clinical testing. The 2 groups were matched for blood pressure and the cardiac ejection fraction. None of the subjects had a prestudy diagnosis of cardiac amyloidosis. Carriers of the amyloidogenic allele were found to have statistically significant increases in the occurrence of many of the echocardiographic features of cardiac amyloidosis relative to the noncarriers and a higher frequency of congestive heart failure and atrial fibrillation. The observations suggest that TTR V122I represents a substantial risk for clinically significant cardiac amyloidosis in elderly African American men, behaving as an age-dependent autosomal dominant disease-associated allele. The diagnosis is difficult to make but can be suspected in African Americans aged >60 years on the basis of age, echocardiographic evidence of diastolic dysfunction, and interventricular septal thickening, even in the absence of more recently available sophisticated echocardiographic techniques for evaluating long-axis function and cardiac magnetic resonance imaging. Positive results for the amyloidogenic TTR V122I allele support the diagnosis and define the origin of the disease, which can be confirmed by endomyocardial biopsy.

Percutaneous PFO closure for the prevention of recurrent brain abscess

A patent foramen ovale (PFO) can act as a conduit between the venous and arterial circulations, allowing right‐to‐left shunting and bypass of the pulmonary circulation. Brain abscess may develop as a result of paradoxical embolism of organisms through a PFO. In this small series, we report on the closure of PFO for the prevention of recurrent brain abscess. Only prospective, randomized trials comparing PFO closure to conservative therapy could provide a definitive answer as to the optimal strategy for preventing recurrent cerebral abscess.

Isolated Subclavian Artery Aneurysm: Evaluation by Transesophageal Echocardiography

A 50‐year‐old man was evaluated following a motor vehicle accident. Chest X‐ray showed a widened mediastinum. Transesophageal echocardiography was helpful in identifying the left subclavian artery and in demonstrating an isolated subclavian artery aneurysm. The TEE findings correlated well with the results of chest CT. Using TEE for the identification of the aortic branches in patients with chest trauma may be critical. (ECHOCARDIOGRAPHY, Volume 21, January 2004)

The A-Dip of Aortic Regurgitation

Echocardiography has become the diagnostic technique of choice for delineating the intracardiac hemodynamics in a host of pathophysiologic states. Pressures and flows can be estimated or measured with enough accuracy to allow for clinical decision-making. We present a case with an unusual Doppler echocardiographic finding and discuss its derivation.

Clinical improvement with repeated courses of intravenous B-type natriuretic peptide in refractory heart failure.

Congestive heart failure (CHF) is characterized by increased salt and water retention by the kidneys in response to decreased renal blood flow. Increased sympathetic nerve activity is also seen in response to a low cardiac output. Although these compensatory mechanisms are initially important for augmenting cardiac output in a failing ventricle, they ultimately lead to volume overload. B-type natriuretic peptide (BNP), a hormone secreted by the heart in response to increased left ventricular wall tension, is now available as a pharmacolgic agent. BNP interferes with renal mechanisms for salt and water retention and may also inhibit sympathetic nerve activity. We report a patient with New York Heart Association (NYHA) class IV CHF who had dramatic, cyclic clinical improvement due to three repeated courses of intravenous BNP. This patient’s marked improvement in clinical and hemodynamic parameters with BNP was superior to that seen in other patients we have treated with intravenous inotropes.

The enigma of occult mitral regurgitation in a patient with cardiogenic shock

In patients with mitral regurgitation (MR), there is a high pressure gradient between the left ventricle (LV) and left atrium that Doppler echocardiography can easily detect. We present a case where transthoracic echocardiography (TTE) failed to provide an accurate evaluation of a patient who presented in cardiogenic shock. A transesophageal echocardiogram diagnosed MR because of a flail leaflet caused by a ruptured papillary muscle in the setting of normal ventricular function.