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Biomedical subjects

Tasneem Z Naqvi

Publications and source records attributed to Tasneem Z Naqvi.

At least 19 recordsLinked to original sources
PubMed2006

Echo-driven V-V optimization determines clinical improvement in non responders to cardiac resynchronization treatment.

Echocardiography plays an integral role in the detection of mechanical dyssynchrony in patients with congestive heart failure and in predicting beneficial response to cardiac resynchronization treatment. In patients who derive sup-optimal benefit from biventricular pacing, optimization of atrioventricular delay post cardiac resynchronization treatment has been shown to improve cardiac output. Some recent reports suggest that sequential ventricular pacing may further improve cardiac output. The mechanism whereby sequential ventricular pacing improves cardiac output is likely improved inter and possibly intraventricular synchrony, however these speculations have not been confirmed. In this report we describe the beneficial effect of sequential V-V pacing on inter and intraventricular synchrony, cardiac output and mitral regurgitation severity as the mechanisms whereby sequential biventricular pacing improves cardiac output and functional class in 8 patients who had derived no benefit or had deteriorated after CRT. Online tissue Doppler imaging including tissue velocity imaging, tissue synchronization imaging and strain and strain rate imaging were used in addition to conventional pulsed wave and color Doppler during sequential biventricular pacemaker programming.

Aged↗
PubMed2006

Novel insights on effect of atrioventricular programming of biventricular pacemaker in heart failure--a case series.

BACKGROUND: Echocardiography plays an integral role in the diagnosis of congestive heart failure including measurement of left heart pressure as well as mechanical dyssynchrony. METHODS: In this report we describe novel therapeutic uses of echo pulsed wave Doppler in atrioventricular pacemaker optimization in patients who had either not derived significant symptomatic benefit post biventricular pacemaker implantation or deteriorated after deriving initial benefit. In these patients atrioventricular optimization showed novel findings and improved cardiac output and symptoms. RESULTS: In 3 patients with Cheyne Stokes pattern of respiration echo Doppler showed worsening of mitral regurgitation during hyperpneac phase in one patient, marked E and A fusion in another patient and exaggerated ventricular interdependence in a third patient thus highlighting mechanisms of adverse effects of Cheyne Stokes respiration in patients with heart failure. All 3 patients required a very short atrioventricular delay programming for best cardiac output. In one patient with recurrent congestive heart failure post cardiac resynchronization, mitral inflow pulse wave Doppler showed no A wave until a sensed atrioventricular delay of 190 ms was reached and showed progressive improvement in mitral inflow pattern until an atrioventricular delay of 290 ms. In 2 patients atrioventricular delay as short as 50 ms was required to allow E and A separation and prevent diastolic mitral regurgitation. All patients developed marked improvement in congestive heart failure symptoms post echo-guided biv pacemaker optimization. CONCLUSION: These findings highlight the value of echo-guided pacemaker optimization in symptomatic patients post cardiac resynchronization treatment.

Aged↗
PubMed2006

The effect of granulocyte colony stimulating factor on regional and global myocardial function in the porcine infarct model.

BACKGROUND: Stem cell therapy has been shown to attenuate the reduction of left ventricular function following myocardial infarction. Most studies have utilized either a direct injection or intra-coronary infusion of cells, but cytokine mobilization of stem cells in the murine model of acute myocardial infarction has been reported to induce similar improvement in cardiac function. METHODS: An antero-apical infarction was induced in swine by balloon occlusion, followed by the daily administration of granulocyte colony stimulating factor (G-CSF) or placebo for 5 days. We used left ventricular angiograms and 2D echocardiograms to assess global function, and 3D echocardiograms to assess regional function prior to infarction, immediately following infarction, and at 8 weeks. Histologic evaluation was performed after sacrifice at 8 weeks. RESULTS: There was no significant difference in early or late post-infarction left ventricular ejection fraction or in myocardial histology between the two groups. Following G-CSF therapy, however, 3D echocardiography demonstrated that the regional ejection fractions of the infarcted segments showed a 50.3% improvement in the G-CSF pigs compared to a 7.4% deterioration in the untreated pigs (p=0.005). CONCLUSIONS: Global left ventricular ejection fraction remained unchanged, and there is no histologic evidence for infarct attenuation following G-CSF infusion in the porcine infarct-reperfusion model. There was recovery of regional function in the infarcted segment in the G-CSF pigs. These data suggest that bone marrow mobilization in larger species has limited potential as a therapy designed to replace infarcted myocardium or to improve overall cardiac function, although further studies are needed to examine regional effect in the infarct area.

Animals↗
PubMed2006

Noninvasive low-frequency ultrasound energy causes vasodilation in humans.

OBJECTIVES: We evaluated the potential vasodilator effects of transcutaneous low-frequency ultrasound (US) in human brachial arteries. BACKGROUND: Recent data show that transthoracic low-frequency US energy results in canine coronary artery vasodilation. METHODS: Brachial artery diameters were measured before and after low-frequency US (29 kHz, 1.4 W/cm2) exposure using US imaging with a linear-array transducer. We assessed the time course of diameter changes after US in 20 subjects. In 10 of 20 subjects, brachial artery flow-mediated vasodilation (FMD) was measured to compare the effect of US to a standard method of evaluating endothelial function. RESULTS: Significant vasodilation was seen after 2 min of US compared with baseline values. At 5 min of US, the brachial artery diameter increased by 4.1%. In addition, the arteries continued to dilate after US exposure. At 3 min after US there was a 5.4%, and at 5 min after US a 6.0% increase in vessel diameter (p < 0.001). These diameters returned to baseline dimensions about 20 min after stopping US. Ultrasound-mediated vasodilation and percentage FMD showed good correlation (r = 0.87; p < 0.001). CONCLUSIONS: This is the first study to demonstrate that noninvasive transcutaneous low-frequency US energy dilates human brachial arteries. This arterial vasodilator effect has a rapid onset (within 2 min), lasts about 20 min, and is similar in magnitude to that of FMD. The vasodilator effect of US may have diagnostic and therapeutic potential in patients with or at risk for vascular disease.

Adult↗
PubMed2006

From vulnerable plaque to vulnerable patient--Part III: Executive summary of the Screening for Heart Attack Prevention and Education (SHAPE) Task Force report.

Screening for early-stage asymptomatic cancers (eg, cancers of breast and colon) to prevent late-stage malignancies has been widely accepted. However, although atherosclerotic cardiovascular disease (eg, heart attack and stroke) accounts for more death and disability than all cancers combined, there are no national screening guidelines for asymptomatic (subclinical) atherosclerosis, and there is no government- or healthcare-sponsored reimbursement for atherosclerosis screening. Part I and Part II of this consensus statement elaborated on new discoveries in the field of atherosclerosis that led to the concept of the "vulnerable patient." These landmark discoveries, along with new diagnostic and therapeutic options, have set the stage for the next step: translation of this knowledge into a new practice of preventive cardiology. The identification and treatment of the vulnerable patient are the focuses of this consensus statement. In this report, the Screening for Heart Attack Prevention and Education (SHAPE) Task Force presents a new practice guideline for cardiovascular screening in the asymptomatic at-risk population. In summary, the SHAPE Guideline calls for noninvasive screening of all asymptomatic men 45-75 years of age and asymptomatic women 55-75 years of age (except those defined as very low risk) to detect and treat those with subclinical atherosclerosis. A variety of screening tests are available, and the cost-effectiveness of their use in a comprehensive strategy must be validated. Some of these screening tests, such as measurement of coronary artery calcification by computed tomography scanning and carotid artery intima-media thickness and plaque by ultrasonography, have been available longer than others and are capable of providing direct evidence for the presence and extent of atherosclerosis. Both of these imaging methods provide prognostic information of proven value regarding the future risk of heart attack and stroke. Careful and responsible implementation of these tests as part of a comprehensive risk assessment and reduction approach is warranted and outlined by this report. Other tests for the detection of atherosclerosis and abnormal arterial structure and function, such as magnetic resonance imaging of the great arteries, studies of small and large artery stiffness, and assessment of systemic endothelial dysfunction, are emerging and must be further validated. The screening results (severity of subclinical arterial disease) combined with risk factor assessment are used for risk stratification to identify the vulnerable patient and initiate appropriate therapy. The higher the risk, the more vulnerable an individual is to a near-term adverse event. Because <10% of the population who test positive for atherosclerosis will experience a near-term event, additional risk stratification based on reliable markers of disease activity is needed and is expected to further focus the search for the vulnerable patient in the future. All individuals with asymptomatic atherosclerosis should be counseled and treated to prevent progression to overt clinical disease. The aggressiveness of the treatment should be proportional to the level of risk. Individuals with no evidence of subclinical disease may be reassured of the low risk of a future near-term event, yet encouraged to adhere to a healthy lifestyle and maintain appropriate risk factor levels. Early heart attack care education is urged for all individuals with a positive test for atherosclerosis. The SHAPE Task Force reinforces existing guidelines for the screening and treatment of risk factors in younger populations. Cardiovascular healthcare professionals and policymakers are urged to adopt the SHAPE proposal and its attendant cost-effectiveness as a new strategy to contain the epidemic of atherosclerotic cardiovascular disease and the rising cost of therapies associated with this epidemic.

Coronary Artery Disease↗
PubMed2006

Rationale and design: the VALsartan In Diastolic Dysfunction (VALIDD) Trial: evolving the management of diastolic dysfunction in hypertension.

BACKGROUND: Although 50% of hypertensive patients in the community are estimated to have diastolic dysfunction, there is no specific guideline for diastolic dysfunction therapy at present despite the condition's clear association with increased cardiovascular risk. Although the efficacy of angiotensin II receptor blockers (ARBs) in hypertension and left ventricular hypertrophy regression has been established, the effect of angiotensin II receptor blockade on intrinsic parameters of diastolic function has not been evaluated in large-scale studies. METHODS: The VALIDD Trial is an investigator-initiated randomized, controlled, double-blind clinical trial on approximately 350 patients designed to explore whether antihypertensive therapy with the ARB valsartan, in addition to standard therapy, would improve intrinsic diastolic properties of the myocardium in patients with hypertension and evidence of diastolic dysfunction. The result of such therapy will be compared with placebo after 38 weeks of treatment. The primary efficacy variable is change in early diastolic lateral mitral annular relaxation velocity measured by tissue Doppler imaging on week 38. CONCLUSIONS: We expect the VALIDD Trial to provide novel insights into the specific effects of ARBs on diastolic dysfunction, as assessed by tissue Doppler imaging, in hypertensive patients. The trial may provide clinically useful data on whether such therapy can directly improve diastolic function in patients with hypertension.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2006

Intracardiac echocardiography for percutaneous mitral valve repair in a swine model.

BACKGROUND: High-quality live imaging assessment of cardiac valves and cardiac anatomy is crucial for the success of percutaneous catheter-based mitral valve (MV) repair techniques. We examined the use of intracardiac echocardiography (ICE) in providing online ICE images necessary for successful perctunaneous MV repair by Alfieri stitch technique-based percutaneous edge-to-edge device in a swine model. METHODS: ICE was performed in 20 healthy adult pigs (90 +/- 8 kg, mean +/- SEM). A 10F ICE catheter was advanced through the left femoral vein and the right jugular vein. Images were obtained from the right atrium, left atrium, right ventricle, and pulmonary artery. Fluoroscopy was used to locate the position of ICE catheter tip in different imaging windows. RESULTS: An echocardiographic protocol was developed for focused visualization of target cardiac structures during the process of percutaneous MV repair. This included visualization of interatrial septum to guide transeptal puncture; to confirm transit of guidewire into the left atrium, across the MV into the left ventricle and across the aortic valve into the aorta; to assist in central positioning of guide catheter in the left atrium above and then across MV leaflets; and to visualize middle scallops of anterior and posterior MV leaflets in short- and long-axis views. Finally, location and orientation of the orifice of the therapy catheter against each MV leaflet was visualized to enable successful capture of MV leaflets, to confirm successful deployment of suture and double orifice (figure of 8" appearance of MV, and finally to confirm central deployment of clip at the site of suture. CONCLUSION: An ICE protocol was developed to visualize serial cardiac structures to guide deployment of suture into the A2-P2 scallops of the MV and to confirm final result before release of clip.

Animals↗
PubMed2006

A new window of opportunity in echocardiography.

BACKGROUND: Improvements in echocardiographic technology have made technically difficult studies a rare entity. However, physical barriers such as bandages, inability for patients to turn because of intubation, arterial lines, and organ and life support machines make echocardiographic imaging challenging. METHODS: We performed echocardiographic imaging from left and right posterior thoracic approach using acoustic properties of pleural fluid to assist in obtaining good imaging windows in patients who had pleural effusion (PE). In this study we describe one author's (T. Z. N.) experience with the mid to lower posterior thoracic window in 18 patients who had PE and in whom conventional transthoracic windows either provided suboptimal images or incomplete clinical information. RESULTS: The posterior approach allowed excellent differentiation of pericardial effusion versus PE, detection of pericardial disease and pericardial infiltration, and excellent endocardial border definition of left and right ventricle in those with poor anterior transthoracic windows. Native and prosthetic aortic valve gradients could be assessed adequately as a result of perfectly parallel Doppler alignment beam to left ventricular outflow tract and aortic valve. In addition, right posterior thoracic window provided views comparable with subcostal view and allowed visualization of inferior vena cava, right atrium, and liver. CONCLUSION: In patients with PE, imaging from low to midposterior thorax can provide additional diagnostic echocardiographic images and should be used in patients in whom conventional images are technically difficult or require additional information.

Adolescent↗
PubMed2006

Stress echocardiography in octogenarians: transesophageal atrial pacing is accurate, safe, and well tolerated.

The feasibility and diagnostic accuracy of transesophageal pacing stress echocardiography for detection of inducible myocardial ischemia were evaluated in 161 patients 80 years of age or older (mean 84 +/- 3.9, range 80-97). The pacing time was 5.5 +/- 2.5 minutes with a total test time of 37 +/- 7 minutes. The mean achieved heart rate was 96 +/- 7% (83%-121%) of maximum predicted with an average rate pressure product of 21,560 +/- 5175 beats/min x mm Hg. There were minor adverse events in 8% of cases and no major complications occurred. Patient acceptance was high. When compared with myocardial single photon emission computed tomography, pacing stress echocardiography had a sensitivity of 89% and a specificity of 93% for the detection of myocardial ischemia, and 91% agreement (kappa = 0.80, P < .001). We demonstrate that pacing stress echocardiography is safe and accurate for detection of myocardial ischemia and, thus, a reliable substitute to exercise and pharmacologic stress testing in octogenarians.

Aged, 80 and over↗
PubMed2005

Comparison of usefulness of left ventricular diastolic versus systolic function as a predictor of outcome following primary percutaneous coronary angioplasty for acute myocardial infarction.

Left ventricular (LV) diastolic function is an important predictor of morbidity and mortality after acute myocardial infarction (AMI). We evaluated the role of diastolic function in predicting in-hospital events and LV ejection fraction (EF) 6 months after a first AMI that was treated with primary percutaneous coronary intervention (PCI). We prospectively enrolled 59 consecutive patients who were 60 +/- 15 years of age (48 men), presented at our institution with their first AMI, and were treated with primary PCI. Patients underwent 2-dimensional and Doppler echocardiography, including tissue Doppler imaging of 6 basal mitral annular regions within 24 hours after primary PCI and were followed until discharge. Clinical and echocardiographic variables at index AMI were compared with a combined end point of cardiac death, ventricular tachycardia, congestive heart failure, or emergency in-hospital surgical revascularization. Follow-up echocardiographic assessment was performed at 6 months in 24 patients. During hospitalization, 3 patients died, 7 developed congestive heart failure, 4 had ventricular tachycardia, and 1 required emergency surgical revascularization. Stepwise logistic regression analysis showed the ratio of early mitral inflow diastolic filling wave (E) to peak early diastolic velocity of non-infarct-related mitral annulus (p < 0.01) (E') and mitral inflow E-wave deceleration time (p < 0.02) to be independent predictors of in-hospital cardiac events (generalized R2 = 0.66). In a stepwise multiple linear regression model, independent predictors of follow-up LVEF were mitral inflow deceleration time (R2 = 0.39, p = 0.002), baseline LVEF (R2 = 0.54, p < 0.02), and mitral inflow peak early velocity/mitral annular peak early velocity (or E/E') of infarct annulus (R2 = 0.66, p = 0.02). In conclusion, in patients who are treated with primary PCI for a first AMI, E/E' velocity ratio and mitral inflow E-wave deceleration time are strong predictors of in-hospital cardiac events and of LVEF at 6-month follow-up.

Aged↗
PubMed2005

Comparison of effectiveness of hand-carried ultrasound to bedside cardiovascular physical examination.

This study compared the accuracy of cardiovascular diagnoses by medical students operating a small hand-carried ultrasound (HCU) device with that of board-certified cardiologists using standard physical examinations. Sixty-one patients (38% women; mean age 70 +/- 19 years) with clinically significant cardiac disease had HCU studies performed by 1 of 2 medical students with 18 hours of training in cardiac ultrasound and physical examinations by 1 of 5 cardiologists. Diagnostic accuracy was determined by standard echocardiography. Two-hundred thirty-nine abnormal findings were detected by standard echocardiography. The students correctly identified 75% (180 of 239) of the pathologies, whereas cardiologists found 49% (116 of 239) (p <0.001). The students' diagnostic specificity of 87% was also greater than cardiologists' specificity of 76% (p <0.001). For nonvalvular pathologies (115 findings), students' sensitivity was 61%, compared with 47% for cardiologists (p = 0.040). There were 124 clinically significant valvular lesions (111 regurgitations, 13 stenoses). Students' and cardiologists' sensitivities for recognizing lesions that cause a systolic murmur were 93% and 62% (p <0.001), respectively. Students' sensitivity for diagnosing lesions that produce a diastolic murmur was 75%; cardiologists recognized 16% of these lesions (p <0.001). The diagnostic accuracy of medical students using an HCU device after brief echocardiographic training to detect valvular disease, left ventricular dysfunction, enlargement, and hypertrophy was superior to that of experienced cardiologists performing cardiac physical examinations.

Aged↗
PubMed2005

Cardiovascular disease in women: sex differences in presentation, risk factors, and evaluation.

Cardiovascular disease (CVD) is the leading cause of mortality in women. Pathophysiology, risk factors, clinical presentation, and outcomes of coronary artery disease (CAD) differ in women, and a better understanding of the sex differences in these factors will potentially lead to a slowing of this epidemic in women. Often forgotten, women have higher complication rates post revascularization and higher in-hospital mortality post myocardial infarction compared with men despite a smaller burden of disease in women. Though overall women share the same risk factors as men in the development of CAD, certain risk factors appear to be particularly ominous, such as the presence of diabetes mellitus, low values of high-density lipoprotein cholesterol, high triglycerides, and psychologic depression. Disease detection in advanced CAD is more accurate with stress echocardiography (ECG) and perfusion single-photon emission computed tomography imaging in women than with stress ECG. Subclincial atherosclerotic disease detection with carotid artery intima media thickness assessment provides an opportunity to target preventive measures in women. This article focuses on some of the sex-specific differences.

Coronary Artery Disease↗
PubMed2005

Chloroquine-induced cardiomyopathy-echocardiographic features.

A 61-year-old woman with a 30-year history of systemic lupus erythematosus treated with chloroquine sulfate presented with complete heart block, congestive heart failure, and findings of restrictive cardiomyopathy on echocardiogram. Thickening of mitral, aortic, and tricuspid valves along with mild to moderate valve regurgitation was also present. Magnetic resonance imaging showed increased gadolinium uptake in the interventricular septum and the left ventricular lateral wall. Endomyocardial biopsy specimen showed marked myocardial cytoplasmic vacuolation and extensive myelin figures. Seven months after discontinuation of chloroquine, she showed significant clinical improvement and reversal of cardiomyopathy on echocardiography. This is the first case report describing a cardiomyopathy with prolonged use of chloroquine involving the conduction system, cardiac valves, and the myocardium with reversal on discontinuation of the drug.

Antirheumatic Agents↗
PubMed2005

Predictors of mortality in paravalvular abscess.

BACKGROUND: Paravalvular abscess formation is an ominous complication of infective endocarditis; however, prognostic variables in paravalvular abscess are poorly defined. METHODS: We examined our experience in patients with paravalvular abscess between 1987 and 2004. Clinical, echocardiographic, microbiologic, and surgical data were examined. RESULTS: There were 45 patients (17 females), age 57 +/- 17 years. Twenty-four patients had prosthetic valve endocarditis. Methicillin-sensitive Staphylococcus aureus and coagulase-negative S. aureus were the most common organisms accounting for 25 (56%) cases. Thirty-eight patients (84%) underwent surgery during initial admission. Surgical mortality was 7%, in-hospital mortality was 31%, and 1-year mortality was 38%. Between patients who died and patients who survived, there were no differences in age (61 +/- 20 years vs 55 +/- 15 years, P = .3), type of microorganism, presence of prosthetic heart valves (47% vs 57%), presence of moderate to severe or severe regurgitation of involved valve (47% vs 57%, P = .37), presence of associated valvular vegetation (93% vs 93%), area of abscess (5.6 +/- 2.9 cm2 vs 4.4 +/- 3.2 cm2, P = .39), left ventricular systolic function (56% +/- 13% vs 56% +/- 10%, P = .9), white cell count (13 +/- 4 vs 13 +/- 7, P = .9), or polymorphonuclear leukocytosis (86% +/- 6% vs 81% +/- 9%, P = .1). Patients who died were sicker on admission compared with those who survived (33% had stroke or altered mental status vs 7%, P = .03) and had worse renal function compared with those who survived (creatinine 4 +/- 4 mg/dL vs 1.6 +/- 1.9 mg/dL, P = .009). CONCLUSION: Neurologic impairment and renal impairment are significant determinants of 1-year survival in patients who present with paravalvular abscess.

Abscess↗
PubMed2004

Comparison of frequency of left ventricular wall motion abnormalities in patients with a first acute myocardial infarction with versus without left ventricular hypertrophy.

One hundred fifty patients with their first acute myocardial infarctions (AMIs) were studied. AMIs were confirmed by troponin levels, ST-segment elevation, or angiographic coronary occlusion. In 36% of patients (16 of 45) with left ventricular (LV) hypertrophy, the wall motion score index was normal, whereas in patients with no LV hypertrophy, only 18% (19 of 105) had no segmental wall motion abnormalities (p = 0.03). When adjusting for troponin level, the odds ratio for normal wall motion of patients with LV hypertrophy was 2.86 (95% confidence interval 1.26 to 6.50) compared with those with normal wall thickness. Consequently, normal LV wall motion by echocardiography in the setting of LV hypertrophy does not exclude AMI.

Aged↗
PubMed2004

Usefulness of a hand-carried cardiac ultrasound device for bedside examination of pericardial effusion in patients after cardiac surgery.

To identify the incidence of pericardial effusion in patients after cardiac surgery using a hand-carried cardiac ultrasound device, 200 patients were assessed on postoperative day 3. If a pericardial effusion was found, patients were monitored for 3 consecutive days with a hand-carried cardiac ultrasound device. Within 72 hours after surgery, 43 patients (21.5%) had developed an effusion, of whom 2 patients had cardiac tamponade and 41 patients (21%) had a small pericardial effusion. No difference was found in the incidence of effusion based on the type of cardiac surgery. Of patients with a small pericardial effusion on day 3 after surgery, an additional 2 of 41 (5%) developed cardiac tamponade.

Cardiac Surgical Procedures↗