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Biomedical subjects

P A Tunick

Publications and source records attributed to P A Tunick.

At least 19 recordsLinked to original sources
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↗
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

Effects of intraaortic balloon counterpulsation on carotid artery blood flow.

BACKGROUND: The intraaortic balloon pump has been shown to improve cardiac output and diastolic coronary flow. Animal studies with balloon counterpulsation have shown variable effects on carotid and cerebral blood flow. We investigated the effects of counterpulsation with the intraaortic balloon pump on blood flow in the common carotid artery in human beings. METHODS AND RESULTS: We studied 14 patients who had an intraaortic balloon pump placed for clinical indications; 9 were hypotensive (4 in the setting of an acute myocardial infarction and 5 immediately after cardiac surgery). Five patients required counterpulsation after undergoing complicated coronary angioplasty. Common carotid artery blood flow was assessed with carotid Duplex scanning both with and without 1:1 balloon augmentation. We found no net increase in the total blood flow in the common carotid artery with intraaortic balloon counterpulsation. This result occurred despite a significant mean increase in both the peak flow velocity and flow velocity integral of the augmented diastolic flows by 160% and 78%, respectively. Total flow did not change because an early systolic reversal of blood flow was seen only with balloon augmentation, which negated the augmented diastolic flow. CONCLUSION: Despite a significant augmentation in diastolic blood flow with balloon counterpulsation, no increase occurred in total carotid artery blood flow. This appeared to be caused by improper timing of balloon deflation. This could result in no improvement in cerebral blood flow with intraaortic balloon pump counterpulsation in critically ill patients.

Adult↗
PubMed1998

Utility of three-dimensional echocardiography during balloon mitral valvuloplasty.

OBJECTIVES: We investigated the role of three-dimensional echocardiography in assessing mitral valve anatomy in greater detail in patients immediately before and after balloon mitral valvuloplasty (BMV). BACKGROUND: Three-dimensional echocardiography is a recently developed, evolving imaging technique that allows visualization of intracardiac structures from any perspective. METHODS: We studied 19 patients undergoing BMV using transesophageal echocardiography (TEE) (Chicago, Illinois) to image the mitral valve. The TEE was interfaced to a TomTec three-dimensional workstation that allows electrocardiographic and respiratory cycle gated image acquisition. The acquired images are digitized, and after postprocessing a three-dimensional image is reconstructed. The mitral valve was viewed "en-face" as if looking up from the left ventricle. RESULTS: The mean mitral valve area (by pressure half-time from the Doppler of the two-dimensional echocardiogram) increased after BMV from 0.86+/-0.06 cm2 to 2.07+/-0.10 cm2, p < 0.0001. This was similar to the mitral valve areas obtained by planimetry from the three-dimensional images. The three-dimensional reconstructions showed a complete commissural split in 10 patients and partial splitting in 9 patients. In three of the eight patients who had an increase in the amount of mitral regurgitation secondary to BMV, the three-dimensional reconstructions were able to detect tears within the valve leaflet. One leaflet tear actually extended up to the mitral valve annulus and was associated with the only case of severe mitral regurgitation. CONCLUSIONS: The three-dimensional echocardiographic reconstruction enabled visualization of the mitral valve so that commissural splitting and leaflet tears not seen on the two-dimensional echocardiogram became visible.

Adolescent↗
PubMed1998

Emboli in transit: the missing link.

Since they were first described in 1990, there has been great interest in protruding atheromas in the aortic arch and descending thoracic aorta as an important source of stroke and other embolic phenomena. This report describes a patient with severe protruding aortic atheromas who died of documented embolic phenomena, in whom actual emboli in transit were seen for the first time during transesophageal echocardiography of the aorta.

Aged↗
PubMed1998

Ultrasound evaluation of endovascular repair of abdominal aortic aneurysms.

UNLABELLED: Endovascular repair of an abdominal aortic aneurysm (AAA) offers a minimally invasive alternative to an open surgical procedure in selected patients. The purpose of this study was to examine the usefulness of ultrasonography for evaluating the results of endovascular repair. METHODS: We studied 17 patients who underwent endovascular repair. In 10 patients a bifurcated prosthesis was positioned below the renal arteries with the bifurcated branches in the iliac arteries. The other 7 patients had a nonbifurcated infrarenal prosthesis. RESULTS: In each patient the AAA and the entire prosthesis, including its bifurcated branches, were visualized. The mean AAA diameter was 5.0 +/- 0.6 cm. The mean prosthesis body diameter was 2.2 +/- 0.3 cm, and the diameters of the bifurcated limbs were 1.0 to 1.2 cm. Color Doppler studies revealed blood flow limited to the prosthetic lumen and its bifurcation in 16 patients; the space between the prosthesis and the AAA wall was clotted in these patients. In 1 patient a communication was seen between the prosthesis and the AAA lumen through a dehiscence in the distal attachment. CONCLUSION: Ultrasonography is a simple, noninvasive tool for the evaluation of the results of endovascular repair of AAA and can detect complications of this procedure.

Aged↗
PubMed1998

Large gradient across a partially ligated left atrial appendage.

The left atrial appendage is frequently ligated during mitral valve surgery to decrease the future risk of embolic events. The postoperative detection of a partially occluded left atrial appendage has previously been reported with the use of transesophageal echocardiography. We describe an unusual case in which Doppler echocardiography demonstrated a remarkably high-velocity jet emanating from a partially ligated left atrial appendage.

Echocardiography, Transesophageal↗
PubMed1997

Atheromatous disease of the thoracic aorta: pathologic and clinical implications.

PURPOSE: To review recent developments in the diagnosis, clinical epidemiology, pathology, and management of atherosclerosis of the thoracic aorta, especially atherosclerosis of the thoracic aorta as a source of embolization. DATA SOURCES: MEDLINE searches, bibliographies of published papers, and consultation with experts in the field. STUDY SELECTION: English-language publications on atherosclerosis of the thoracic aorta were selected. DATA SYNTHESIS: During the last 6 years, the increasing use of transesophageal echocardiography has shown that atherosclerotic plaque in the thoracic aorta is a source of otherwise unexplained embolic events, including stroke, transient ischemic attack, and peripheral emboli. Retrospective studies have documented a strong independent association between larger lesions (4 mm to 5 mm) and previous embolic disease, and prospective studies have shown that patients with these lesions have a high risk for future events (in one study, the risk for stroke was 12%; in another, the risk for cerebral or peripheral events was 33% in a follow-up period of just 14 months). These lesions also pose a serious risk for embolization caused by manipulation of the aorta during catheterization, intra-aortic balloon-pump placement, and cannulation of the aorta for heart surgery. Pathologic examination has shown atherosclerotic plaque, often with superimposed thrombi that account for the mobile components seen on transesophageal echocardiography. The management of patients who have atherosclerotic lesions in the thoracic aorta has not been determined prospectively. However, anticoagulation may help prevent emboli, as it does for patients who have thrombi in other locations, such as the left atrium and the left ventricle. CONCLUSIONS: Protruding atherosclerotic lesions in the thoracic aorta, often with superimposed mobile thrombi, are an important cause of embolic disease. Transesophageal echocardiography should be considered in the work-up of patients who have unexplained embolic events.

Aorta, Thoracic↗
PubMed1997

Correlation between plasma homocyst(e)ine and aortic atherosclerosis.

Plasma homocyst(e)ine [H(e)] levels correlate with the prevalence of arterial occlusive diseases. Recently, transesophageal echocardiography (TEE) has been used to evaluate patients with atherosclerotic plaques in the thoracic aorta. The purpose of this study was to determine whether H(e) levels correlate with the degree of atherosclerotic plaque in the thoracic aorta (ATH) as seen on TEE. Maximum plaque areas for three locations in the thoracic aorta (arch, proximal descending, and distal descending) were measured with TEE in 156 patients. Maximum plaque areas for these locations were added to yield an estimate of ATH. ATH and H(e) levels, and levels of folic acid, vitamin B12, and pyridoxal 5'-phosphate were measured in a double-blind manner. Univariate analysis demonstrated a significant correlation of H(e) with ATH (r = 0.3, p< 0.001). On multivariate analysis, H(e) was independently predictive of ATH (r for the model including H(e) was 0.63, p < 0.0001). Plasma H(e) levels are therefore significantly and independently correlated with the degree of atherosclerosis in the thoracic aorta.

Aged↗
PubMed1997

Sequential external counterpulsation increases cerebral and renal blood flow.

The purpose of this study was to evaluate the effect of sequential external counterpulsation (SECP) on cerebral and renal blood flow. The effect of SECP on carotid and renal artery blood flow was studied in 35 and 18 patients, respectively. With a portable unit, cuffs were applied to the calves and thighs, sequentially inflated with air at the onset of diastole, and deflated at the onset of systole. Carotid and renal artery Duplex studies were performed during intermittent SECP. Flow velocity and flow velocity integral were measured at baseline and during SECP. Diastolic augmentation of carotid and renal artery flow velocity was observed in all patients. The mean carotid flow velocity integral increased by 22% from 27.7 +/- 1.8 cm to 33.1 +/- 2.3 cm (P = 0.001). The mean renal artery flow velocity integral increased by 19% from 21 +/- 1 cm to 25 +/- 1 cm (P = 0.0001). With SECP, a new diastolic Doppler flow velocity wave was observed, with an average peak carotid diastolic flow velocity of 56 +/- 4 cm/sec and an average peak renal artery diastolic flow velocity of 40 +/- 2.5 cm/sec. This diastolic wave was 75% (carotid) and 68% (renal) as high as the systolic wave during SECP. In addition, with SECP the systolic wave increased by 6% and 8% in the carotid and renal artery, respectively (P = 0.02 and 0.006, respectively). In conclusion, SECP significantly increases carotid and renal blood flow. This noninvasive, harmless treatment may be useful to support patients with decreased cerebral and renal perfusion.

Aged↗
PubMed1997

Reengineering a cardiovascular surgery service.

BACKGROUND: Reengineering, involving the radical redesign of business processes, has been used successfully in a variety of health care settings. In 1994 New York University (NYU) Medical Center (MC) launched its first reengineering team, whose purpose was to redesign the entire process of caring for patients-from referral to discharge-on the cardiovascular (CV) surgery service. REENIGINEERING TEAM: The multidisciplinary CV Surgery Reengineering Team was charged with two goals: improving customer (patient, family, and referring physician) satisfaction and improving profitability. The methodology to be used was based on a reengineering philosophy-discarding basic assumptions and designing the patient care process from the ground up. THE TRANSFER-IN INITIATIVE: A survey of NYU cardiologists, distributed in April 1994, suggested that the organization was considered a difficult place to transfer patients. The team's recommendations led to a new, streamlined transfer-in policy. The average waiting time from when a referring physician requested a patient transfer and the time when an NYUMC physician accepted the transfer decreased from an average of 9 hours under the old system to immediate acceptance. OTHER INITIATIVES: Three customer satisfaction task forces implemented multiple programs to make the service more user friendly. In addition, referrals increased and length of stay decreased, without an adverse impact on the mortality rate. CONCLUSION: For the first time at NYUMC, a multidisciplinary team was given the mandate to achieve major changes in an entire patient care process. Similar projects are now underway.

Cardiology Service, Hospital↗
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↗