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Biomedical subjects

I Kronzon

Publications and source records attributed to I Kronzon.

At least 55 records · Page 3Linked to original sources
PubMed2000

Infiltrative nonamyloidotic monoclonal immunoglobulin light chain cardiomyopathy: an underappreciated manifestation of plasma cell dyscrasias.

BACKGROUND: Infiltrative cardiomyopathies are characterized by diastolic dysfunction. In monoclonal plasma cell dyscrasias, organ compromise may be produced by tissue deposition of monoclonal immunoglobulins or their constituent peptides independently of the effects of unbridled plasma cell proliferation. The deposits may be fibrillar, as in light chain amyloid (AL) or nonfibrillar, as in light chain deposition disease (LCDD). AL disease of the heart is a restrictive cardiomyopathy. We hypothesized that, despite differences in physical properties, nonamyloidotic light chain deposition in the myocardium could produce similar clinical and physiological abnormalities. METHODS: Cardiac tissue from five patients with LCDD and cardiac dysfunction was examined by immunohistochemical and electron microscopic techniques. Hospital charts, electrocardiograms, echocardiograms and cardiac catheterization results were reviewed. In two cases, the original echocardiograms were reanalyzed. RESULTS: The five patients with nonamyloidotic light chain deposits in the myocardium had either mechanical or electrocardiographic abnormalities. In four with adequate clinical documentation, the diastolic dysfunction and conduction abnormalities were similar or identical to that described in cardiac AL disease. CONCLUSIONS: Although nonamyloidotic immunoglobulin light chain deposits in the myocardium differ in distribution and ultrastructural organization from the fibrillar deposits of AL disease, an analogous pattern of diastolic dysfunction and conduction disturbances results. The diagnosis should be considered in patients with a plasmacytic dyscrasia and restrictive cardiomyopathy in whom Congo red staining of endomyocardial biopsy tissue is negative. The diagnosis can be established by using the appropriate immunohistochemical and ultrastructural tissue examinations.

Adult↗
PubMed1999

Association of mitral annular calcium and of aortic cuspal calcium with coronary artery disease in older patients.

In a prospective study, mitral annular calcium (MAC) was present in 274 of 752 men (36%), mean age 80 years, and in 869 of 1,663 women (52%), mean age 82 years (p <0.0001); aortic cuspal calcium was present in 295 of 752 men (39%) and in 672 of 1,663 women (40%) without aortic cuspal calcium (p = NS). Coronary artery disease was present in 150 of 274 men (55%) with versus 192 of 478 men (40%) without MAC (p = 0.0001) and in 446 of 869 women (51%) with versus 276 of 794 women (35%) without MAC (p <0.0001); coronary artery disease was present in 167 of 295 men (57%) with versus 175 of 457 men (38%) without aortic cuspal calcium (p <0.0001), and in 360 of 672 women (54%) with versus 362 of 991 women (37%) without aortic cuspal calcium (p <0.0001).

Aged↗
PubMed1999

Comparison of incidences of congestive heart failure in older African-Americans, Hispanics, and whites.

In a prospective study of 2,893 African-Americans, Hispanics, and whites, mean age 81 years, at 43-month follow-up, congestive heart failure (CHF) developed in 194 of 686 African-Americans (28%), in 67 of 257 Hispanics (26%), and in 533 of 1,950 whites (27%) (p = NS). The Cox regression model showed that significant independent risk factors for CHF were male gender (risk ratio = 1.4, p = 0.0001); hypertension (risk ratio = 2.5, p = 0.0001); coronary artery disease (risk ratio = 4.0, p = 0.0001); diabetes mellitus (risk ratio = 1.6, p = 0.0001); and age (risk ratio = 1.05, p = 0.0001).

Aged↗
PubMed1999

Association of left ventricular hypertrophy and chronic atrial fibrillation with the incidence of new thromboembolic stroke in 2,384 older persons.

In a prospective study of 2,384 persons, mean age 81 years, at 44-month follow-up, new thromboembolic stroke developed in 510 of 2,384 persons (21%). The Cox regression model showed that significant independent risk factors for new thromboembolic stroke were atrial fibrillation (risk ratio 3.2), left ventricular hypertrophy (risk ratio 2.8), prior stroke (risk ratio 2.2), and male gender (risk ratio 1.2).

Aged↗
PubMed1999

Comparison of frequency of new coronary events in older subjects with and without valvular aortic sclerosis.

In a prospective study of 1,980 subjects (mean age 81 +/- 8 years) without valvular aortic stenosis, 981 (50%) had valvular aortic sclerosis diagnosed by 2-dimensional and continuous-wave Doppler echocardiography. Independent risk factors for new coronary events were prior coronary artery disease (p = 0.0001, risk ratio 2.8), male gender (p = 0.002, risk ratio 1.3), and valvular aortic sclerosis (p = 0.0001, risk ratio 1.8).

Aged↗
PubMed1999

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.

Aged↗
PubMed1999

The role of transesophageal echocardiography in the diagnosis and treatment of right atrial thrombi.

Twenty patients with right atrial thrombi were identified through the use of transthoracic and transesophageal echocardiography. Transesophageal echocardiography identified right atrial thrombi in all 20 cases. Transthoracic echocardiography showed definite thrombi in only 6 (30%) cases and suggested thrombus in another 2 (10%) patients. Thus transthoracic echocardiography results were false-negative for right atrial thrombus in 60% of cases. All 3 thrombi found within the right atrial appendage and 2 of 3 thrombi on pacemaker wires were missed by transthoracic echocardiography. There was no significant difference in the mean size between those thrombi seen (1.37 +/- 0.6 cm) and those missed (1.5 +/- 0.9 cm) by transthoracic echocardiography. Transesophageal echocardiography also significantly affected treatment. Anticoagulation was initiated or amplified in 13 patients. In 8 of these 13, thrombi were seen only by transesophageal echocardiography. Surgery was performed to remove thrombi in 7 cases, and in 3 (43%) cases it was because of thrombi seen only by transesophageal echocardiography. This study suggests that transesophageal echocardiography should be performed whenever right atrial thrombi are suspected. Transesophageal echocardiography has a significant effect on the diagnosis and management of patients with right atrial thrombi.

Adolescent↗
PubMed1999

Atheromas of the thoracic aorta: A comparison of transesophageal echocardiography and breath-hold gadolinium-enhanced 3-dimensional magnetic resonance angiography.

Transesophageal echocardiography (TEE) has been the procedure of choice for identifying thoracic aortic atheromas. All patients over a 2-year period who underwent both TEE and magnetic resonance angiography of the thoracic aorta within 1 month were identified. The largest plaque in 3 aortic segments (ascending, arch, and descending) was measured. Thirty patients (16 men; 66.8 +/- 12.9 years) were studied. The mean size of the atheromas in the arch was larger as measured by TEE compared with magnetic resonance angiography (3.4 vs 1.4 mm, P =.01). However, the mean atheroma size was similar in the ascending aorta (1.9 vs 1.3 mm, P =.5) and descending aorta (3.9 vs 3.5 mm, P =.66). Of 24 aortic segments with plaques measuring >/=5 mm (with high embolic risk), 22 (92%) were seen on TEE and only 13 (54%) on magnetic resonance angiography (P =. 003). In conclusion, although both techniques are complementary, TEE does identify more high-risk plaques.

Aged↗
PubMed1999

Incidence of new thromboembolic stroke in persons 62 years and older with chronic atrial fibrillation treated with warfarin versus aspirin.

OBJECTIVE: To investigate the incidence of new thromboembolic (TE) stroke in older persons with chronic atrial fibrillation treated with oral warfarin versus aspirin. DESIGN: In an observational study of 312 older persons with chronic atrial fibrillation, long-term aspirin 325 mg daily was administered to 187 persons, and oral warfarin, in a dose adjusted to maintain the international normalized ratio (INR) between 2.0 and 3.0, was administered to 115 persons. The incidence of new TE stroke was analyzed in persons treated with warfarin versus aspirin at 36 +/- 17 months (1 to 99 months) follow-up. SETTING: A large, long-term healthcare facility. PATIENTS: The patients included 208 women and 104 men, mean age 84 +/- 7 years (range 62 to 101 years). MEASUREMENTS AND MAIN RESULTS: Four of 125 persons (3%) on warfarin stopped taking warfarin compared with four of 187 persons (2%) on aspirin who stopped taking aspirin because of adverse effects (P not significant). In persons with prior stroke, the incidence of new TE stroke was 40% (27 of 67) in persons treated with warfarin versus 81% (56 of 69) in persons treated with aspirin (P < .001). In persons with no prior stroke, the incidence of new TE stroke was 22% (13 of 58) in persons treated with warfarin versus 56% (66 of 118) in persons treated with aspirin (P < .001). The incidence of new TE stroke in all subjects was 32% (40 of 125) in persons treated with warfarin versus 65% (122 of 187) in persons treated with aspirin (P < .001). Cox regression analysis showed that persons taking warfarin had a 76% less chance of developing a new TE stroke than those taking aspirin after controlling the confounding effects of other risk factors. CONCLUSION: In an observational study of older persons with chronic atrial fibrillation, persons treated with oral warfarin to maintain an INR between 2.0 and 3.0 had a significantly lower incidence of new TE stroke than persons treated with oral aspirin 325 mg daily.

Administration, Oral↗
PubMed1998

Utility of transesophageal echocardiography during port-access minimally invasive cardiac surgery.

In this study, we sought to determine the use of transesophageal echocardiography (TEE) as the primary imaging technique to assist in the placement of endovascular catheters during minimally invasive, port-access cardiac surgery. The recent development of endovascular catheters that are placed via the femoral artery and vein has enabled patients to be placed on cardiopulmonary bypass without the need for direct visualization of the heart or great vessels via sternotomy. This has allowed cardiac surgery to be performed through smaller thoracotomy incisions. Placement of these catheters has previously been performed with fluoroscopic guidance, which has major imaging limitations. Thirty-six patients underwent port-access cardiac surgery at our institution during the study period. All patients underwent intraoperative TEE. We used TEE to visualize the coronary sinus os, right atrium and superior vena cava, and thoracic aorta to assist with placement of the coronary sinus catheter, venous cannula, and endoaortic clamp. Twenty patients underwent mitral valve surgery, 14 patients coronary artery bypass grafting, 1 patient aortic valve replacement, and 1 patient repair of an atrial septal defect by the port-access approach. TEE was able to adequately visualize the cardiac structures and assist in the placement of the endovascular catheters in all patients. Fluoroscopy was only helpful as an aid to TEE for placement of the coronary sinus catheter. TEE is an excellent imaging modality for the proper placement of these new endovascular catheters, obviating the need for fluoroscopy, except to be on standby and for placement of the coronary sinus catheter.

Adult↗
PubMed1998

Risk factors for new thromboembolic stroke in patients > or = 62 years of age with chronic atrial fibrillation.

In a prospective study of 312 older patients with chronic atrial fibrillation, at 36-month follow-up evaluation, new thromboembolic stroke developed in 162 of 312 patients (52%). Significant independent risk factors for new thromboembolic stroke were prior stroke (risk ratio = 1.6), rheumatic mitral stenosis (risk ratio = 2.0), left ventricular (LV) hypertrophy (risk ratio = 2.8), abnormal LV ejection fraction (risk ratio = 1.8), serum total cholesterol (risk ratio = 1.005), and serum high-density lipoprotein cholesterol (risk ratio = 0.96).

Adult↗