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Biomedical subjects

I Kronzon

Publications and source records attributed to I Kronzon.

At least 91 records · Page 5Linked to original sources
PubMed1997

Long-term prognostic significance of dobutamine echocardiography in patients with suspected coronary artery disease: results of a 5-year follow-up study.

OBJECTIVES: This study sought to assess the long-term prognostic utility of dobutamine stress echocardiography in predicting fatal and nonfatal cardiac events. BACKGROUND: Although dobutamine stress echocardiography has improved sensitivity and specificity for detection of coronary artery disease, little is known of its predictive value for long-term cardiac events. Therefore, we followed up 120 consecutive patients who underwent dobutamine echocardiography for suspected coronary disease from March 1989 to August 1991. METHODS: All patients presenting for coronary angiography for chest pain were eligible for recruitment. Follow-up was 100% complete at 5 years (range 3.0 to 6.1). Cardiac events were defined as cardiac death or nonfatal myocardial infarction or the need for coronary revascularization (coronary angioplasty or bypass surgery). RESULTS: Positive (n = 78) and negative (n = 42) dobutamine test groups differed in their rates of coronary artery bypass graft surgery (37.2% vs. 9.5%, p < 0.001, respectively) and mortality. Of 26 total deaths, 22 occurred in the group with positive dobutamine test results (28% vs. 9.5%, p < 0.018); all 7 cardiac deaths occurred in this group as well (9% vs. 0%, p < 0.045). By multivariate regression analysis, positive results on dobutamine echocardiography remained independently predictive of future cardiac death after left ventricular ejection fraction and other clinical variables were accounted for. CONCLUSIONS: A positive finding on dobutamine echocardiography is an independent predictor of long-term cardiac mortality, whereas a negative finding confers a significantly reduced likelihood of cardiac death as much as 5 years from initial testing. We conclude that dobutamine stress echocardiography can be used to predict which patients with suspected coronary artery disease are at low risk for cardiac death and do not require concurrent nuclear or invasive testing.

Aged↗
PubMed1997

Prognostic significance of spontaneous echo contrast in the thoracic aorta: relation with accelerated clinical progression of coronary artery disease.

OBJECTIVES: The purposes of this study were to identify the incidence of aortic smoke in an unselected cohort of patients and to determine the utility of this measurement as a clinical marker for future coronary events and long-term cardiac prognosis. BACKGROUND: Although spontaneous echo contrast detected within the cardiac chambers has been associated with an increased risk of thromboembolism, less is known about "smoke" within the thoracic aorta and its relation to progression of coronary artery disease. METHODS: We prospectively assessed 118 unselected, consecutive male patients (mean age 67 years, range 29 to 86) who underwent transesophageal echocardiography (TEE). The presence of aortic smoke was identified by swirling echodense shadows distinct from high gain artifact. A positive result required confirmation by two of three independent observers. RESULTS: Aortic smoke without dissection was found in 25 of the patients (21%). Indications for TEE, coronary risk factors, the incidence of reduced left ventricular ejection fraction and mitral insufficiency and known coronary artery disease severity collectively did not differ significantly at baseline between the groups with and without smoke. Follow-up averaged 20.4 months (range 18 to 24) and was 100% complete for mortality and 98% complete for morbidity. The presence of aortic smoke was an independent predictor of myocardial infarction (16.0% vs. 2.2%, p < 0.005) and cardiac death (20.0% vs. 1.1%, p < 0.0001). These statistics remained significant after covarying for age, ejection fraction < 50%, hypertension, diabetes, aortic dimension, the presence of an atheromatous plaque and smoke in the left atrium. CONCLUSIONS: Spontaneous echo contrast detected within the thoracic aorta by transesophageal echocardiography is a common and important clinical marker that is strongly associated with an increased risk for future myocardial infarction and cardiac mortality. Future studies will attempt to define the pathophysiology of this relation and assess whether aggressive revascularization strategies and antithrombotic therapy may aid in the reduction of this risk.

Adult↗
PubMed1997

Diagnosis and treatment of iatrogenic femoral artery pseudoaneurysm: a review.

A pseudoaneurysm is a pulsatile hematoma that communicates with an artery through a disruption in the arterial wall. Femoral pseudoaneurysm is a common complication of invasive procedures. It occurs in 0.1% to 0.2% of diagnostic angiograms and 3.5% to 5.5% of interventional procedures. Longer procedures, large-bore catheters, anticoagulation, and a faulty lower site of puncture are associated with a higher incidence of femoral pseudoaneurysm. Pseudoaneurysms are associated with the characteristic findings of a pulsatile mass, a palpable thrill, and an audible to-and-fro murmur. The diagnosis is confirmed by imaging of the pseudoaneurysm. A femoral arterial duplex study is the diagnostic imaging modality of choice. It can show the pseudoaneurysm, the degree of clotting, the communication with the femoral artery, and the blood flow velocity pattern within the artery, the communication, and the pseudoaneurysm. Small (less than 2 cm) femoral pseudoaneurysms clot spontaneously and usually require no treatment. Larger femoral pseudoaneurysms may lead to complications including rupture and compression of the adjacent femoral vein (with resulting venous thrombosis) or of the femoral nerve. Treatment may be surgical. However, recently it has been shown that direct, noninvasive compression of the pseudoaneurysm stops the blood flow in the communication and leads to pseudoaneurysm clotting and obliteration.

Aneurysm, False↗
PubMed1997

Transesophageal echocardiographic identification of a retrograde dissection of the ascending aorta caused by inadvertent cannulation of the common carotid artery.

Retrograde aortic dissections can be a complication of vascular procedures. We describe a case of an inadvertent cannulation of the right common carotid artery during an attempt at inserting a pulmonary artery catheter. This resulted in dissection of the right common carotid, subclavian, and innominate arteries. Transesophageal echocardiography was able to visualize a retrograde dissection extending back into the ascending aorta.

Aortic Dissection↗
PubMed1996

The effect of the ingestion of ethanol on obstruction of the left ventricular outflow tract in hypertrophic cardiomyopathy.

BACKGROUND: Ethanol causes vasodilation, which might have an adverse effect, due to increased obstruction of the left ventricular outflow tract, in patients with hypertrophic obstructive cardiomyopathy. We assessed the hemodynamic effects of the ingestion of ethanol, in an amount commonly consumed socially, in patients with hypertrophic cardiomyopathy. METHODS: We performed echocardiography in 36 patients before and several times after the ingestion of either 50 ml of 40 percent ethanol or an isocaloric placebo with the aroma of rum. Each patient received both ethanol and placebo, on different days. The patients, but not the physicians, were blinded to the content of the drink. We measured the sizes of the left atrium and left ventricle, the left-ventricular-wall thickness, blood pressure, heart rate, the degree of systolic anterior motion of the mitral valve, and the pressure gradient across the left ventricular outflow tract. RESULTS: The ingestion of ethanol regulated in a significant drop in the mean (+/- SD) systolic blood pressure (from 130.5 +/- 18.6 to 122.5 +/- 20.3 mm Hg, P<0.001), a significant increase in systolic anterior motion of the mitral valve (from a grade of 2.1 to a grade of 2.5, P<0.001), and a 63 percent increase in the mean gradient across the left ventricular outflow tract (from 38.1 +/- 26.5 to 62.2 +/- 42.4 mm Hg, P<0.001). These changes, which were not associated with symptoms, did not occur after the ingestion of placebo. CONCLUSION: The ingestion of a small amount of ethanol caused an increase in the gradient across the left ventricular outflow tract in patients with hypertrophic obstructive cardiomyopathy, which could have and adverse clinical effect.

Adult↗
PubMed1996

Incomplete occlusion of left ventricular aneurysms after endoventricular aneurysmorrhaphy: diagnosis by echocardiography and ventriculography.

Surgical treatment of left ventricular aneurysms have recently focused on maintaining normal left ventricular geometry by using a circular patch repair to exclude the aneurysmal cavity (endoaneurysmorrhaphy). We describe two patients who underwent this procedure and were subsequently found by echocardiography and angiography to have a residual communication between the left ventricular cavity and the aneurysm which contained thrombus. This finding may have implications regarding the optimal hemodynamic result of the surgery and the risk of thromboembolism.

Adult↗
PubMed1996

Intracardiac shunts.

Unsuspected intracardiac shunts can be a cause of acute deterioration in critically ill patients. Shunts can be acquired or congenital conditions that become symptomatic only with changed physiologic conditions. Transesophageal echocardiography is an excellent tool for the diagnosis of intracardiac shunts.

Aortic Rupture↗
PubMed1996

Evaluation and management of cholesterol embolization and the blue toe syndrome.

The blue toe syndrome is characterized by tissue ischemia secondary to cholesterol crystal or atherothrombotic embolization leading to occlusion of small vessels. Embolization occurs typically from an ulcerated atherosclerotic plaque located in the aorto-iliac-femoral arterial system. Clinical presentation can range from a cyanotic toe to a diffuse multiorgan systemic disease that can mimic other systemic illness. Mortality can be higher than 70% depending on the scope of the illness. Embolization can occur spontaneously or from a variety of insults such as invasive vascular procedures, anticoagulation, or thrombolytic therapy. Angiography, duplex ultrasonography, computerized tomographic scanning, and magnetic resonance imaging have been used to image the offending lesions, with angiography considered the "gold standard" despite its inherent risks. Recently, transesophageal echocardiography has been shown to be a helpful tool in imaging the thoracic aorta and delineating in great detail the anatomy of the aortic atheroma. At present, surgery remains the most viable treatment option. However, we look to the future for large randomized trials to help predict embolization and thus the proper medical therapy.

Blue Toe Syndrome↗
PubMed1995

Endoventricular remodeling of left ventricular aneurysm. Functional, clinical, and electrophysiological results.

BACKGROUND: Recent advances in surgical techniques for the repair of left ventricular aneurysms (LVAs) include the use of an endoventricular patch to exclude the aneurysm cavity. This technique has replaced conventional linear plication of the aneurysm. The endoventricular patch technique remodels the left ventricular cavity to a more physiological geometry that improves function. METHODS AND RESULTS: From December 1989 through November 1993, 45 patients underwent an LVA repair with an endoventricular patch. This procedure was performed in association with coronary artery bypass grafting in 40 patients. Twenty-eight patients (62.2%) also had nonguided encircling subendocardial incisions. Operative procedures included 7 emergency operations, 3 concomitant valve procedures, and a mean of 2.2 bypass grafts per patient. Eight patients had previous cardiac operations. Hospital mortality was 15.6% (7/45) for all patients and 9.1% (3/33) for nonemergent revascularization and LVA repairs. Ejection fraction improved from a mean of 25.8% preoperatively to 37.8% postoperatively; the mean New York Heart Association classification improved from 3.5 to 1.5. Of patients known to have preoperative arrhythmias (inducible or sudden death), 69% were not inducible postoperatively without antiarrhythmic medication. Survival from late cardiac death (including death of unknown origin) was 86.5% at 2 years. Freedom from documented ventricular arrhythmias was 94.3% at 2 years. CONCLUSIONS: These results indicate that the patch endoaneurysmorrhaphy technique can provide an excellent functional and physiological outcome in patients with LVAs and severely impaired ventricular function.

Aged↗
PubMed1995

Left ventricular hypertrophy is more prevalent in patients with systemic hypertension with extracranial carotid arterial disease than in patients with systemic hypertension without extracranial carotid arterial disease.

The mechanism of the association between LV hypertrophy and ECAD is unknown and needs to be investigated. Whether LV hypertrophy in patients with systemic hypertension is a marker for ECAD or contributes to ECAD needs to be investigated. The association between LV hypertrophy and significant ECAD was independent of the level of blood pressure in our patients. Coronary atherosclerosis in our patients with signifciant ECAD may have contributed to the increased prevalence of LV hypertrophy. The association between LV hypertrophy and significant ECAD may contribute to the high incidence of stroke in patients with LV hypertrophy. This is currently under investigation by our group.

Aged↗