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Marmar Vaseghi

Publications and source records attributed to Marmar Vaseghi.

10 recordsLinked to original sources
PubMed2006

Usefulness of preimplantation B-type natriuretic peptide level for predicting response to cardiac resynchronization therapy.

Nearly 1/3 of patients with heart failure (HF) fail to respond to cardiac resynchronization therapy (CRT). The purpose of this study was to evaluate the value of preimplantation brain natriuretic peptide (BNP) in predicting the clinical response to CRT. We retrospectively analyzed 164 patients who underwent CRT. Patients with New York Heart Association functional class III or IV HF symptoms despite maximal medical therapy, who were not on inotropic medications, had left ventricular ejection fraction < or =35%, and QRS duration >130 ms were included in the study. CRT response in patients who survived at 6-month follow-up was defined as no HF hospitalization and improvement of > or =1 grades in the New York Heart Association classification. BNP assays were performed before implantation and at 6-month follow-up. Patients had ischemic (47%) or nonischemic (53%) cardiopathy. Responders (n = 107) and nonresponders (n = 57) had similar baseline characteristics. Cardiac death and hospitalization for HF occurred in 5 (4.7%) and 18 (31.6%) patients, respectively. CRT responders compared with nonresponders exhibited higher preimplantation BNP levels (800 +/- 823 vs 335 +/- 348 pg/ml, p = 0.0002) and a significant reduction in the QRS duration after implantation (-6 +/- 34 vs +7 +/- 32 ms, p = 0.048). The preimplantation BNP was the only independent predictor of the CRT response (p = 0.001). A BNP value > or =447 pg/ml demonstrated a sensitivity of 62% and specificity of 79% in identifying CRT response. In a subgroup of 41 patients who underwent Doppler tissue imaging analysis, the preimplantation BNP was higher in patients presenting with intraventricular dyssynchrony (845 +/- 779 vs 248 +/- 290 pg/ml, p = 0.04). In conclusion, the preimplantation BNP value independently predicts CRT response and was superior to QRS duration reduction in identifying CRT responders.

Biomarkers↗
PubMed2006

Percutaneous intrapericardial echocardiography during catheter ablation: a feasibility study.

BACKGROUND: Percutaneous pericardial access, epicardial mapping, and ablation have been used successfully for catheter ablation procedures. OBJECTIVES: The purpose of this study was to evaluate the safety and feasibility of closed-chest direct epicardial ultrasound imaging for aiding cardiac catheter ablation procedures. METHODS: An intracardiac ultrasound catheter was used for closed-chest epicardial imaging of the heart in 10 patients undergoing percutaneous epicardial access for catheter ablation. All patients underwent concomitant intracardiac echocardiography and preprocedural transesophageal echocardiography. Using a double-wire technique, two sheaths were placed in the pericardium, and a phased-array ultrasound catheter was manipulated within the pericardial sinuses for imaging. RESULTS: Multiple images from varying angles were obtained for catheter navigation. Notably, image stability was excellent, and structures such as the left atrial appendage were seen in great detail. No complications resulting from use of the ultrasound catheter in the pericardium occurred, and no restriction of movement due to the presence of the additional catheter in the pericardial space was observed. Wall motion was correlated to voltage maps in five patients and showed that areas of scars correlated with wall-motion abnormalities. Normal wall-motion score correlated to sensed signals of 4.2 +/- 0.3 mV (normal myocardium >1.5 mV), and scores >1 correlated to areas with signals <0.5 mV in that territory). CONCLUSION: Intrapericardial imaging using an ultrasound catheter is feasible and safe and has the potential to provide additional valuable information for complex ablation procedures.

Adult↗
PubMed2006

Value of high-density endocardial and epicardial mapping for catheter ablation of hemodynamically unstable ventricular tachycardia.

BACKGROUND: Percutaneous epicardial mapping has been used for ablation of recurrent ventricular tachycardia (VT). OBJECTIVES: The purpose of this study was to use a combined epicardial and endocardial mapping strategy to delineate the myocardial substrate for recurrent VT in both ischemic (n = 12) and nonischemic cardiomyopathy (n = 8), and to define the role of epicardial ablation. METHODS: Electroanatomic mapping was performed in 20 patients. High-density voltage maps were obtained by acquiring both endocardial and epicardial electrograms. Electrograms derived from six patients with structurally normal hearts were used as controls. A total of 26 VTs were targeted in the 20 patients. RESULTS: Most VTs (23/26 [88.5%]) were hemodynamically unstable. In patients with ischemic cardiomyopathy, the extent of endocardial scar was greater than epicardial scar. A definable pattern of scar could not be demonstrated in nonischemic cardiomyopathy. Pathologic examination of explanted hearts in two patients with nonischemic cardiomyopathy demonstrated that low-voltage areas were not always predictive of scarred myocardium. A substrate-based approach was used for catheter ablation. Catheter ablation was performed on the endocardium in all patients; additional epicardial delivery of radiofrequency energy was required in 8 (40%) of 20 patients for successful ablation. During follow-up (12 +/- 4 months), 15 (75%) of 20 patients have been arrhythmia-free. CONCLUSION: Patients with ischemic cardiomyopathy tend to have a larger endocardial than epicardial scar. Use of epicardial and endocardial electroanatomic mapping to define the full extent of myocardial scars allows successful catheter ablation in patients with hemodynamically unstable VTs.

Adult↗
PubMed2006

Catheter ablation of right ventricular outflow tract tachycardia: value of defining coronary anatomy.

INTRODUCTION: Thermal damage to coronary arteries during catheter ablation has been previously reported. Coronary artery damage during LV outflow tract ventricular tachycardia is well recognized. However, the relationship of the coronary arteries to the RV outflow tract during catheter ablation has not been delineated. The purpose of this study was to define the relationship between the RV outflow tract and the coronary arteries utilizing arteriography, echocardiography, CT angiography, and gross anatomic pathology. METHODS: The relationship of the coronaries to the RV outflow tract was analyzed in three patients groups: Group 1: patients (n = 10) undergoing RV outflow tract ventricular tachycardia; Group 2: patients (n = 50) undergoing CT coronary angiography; Group 3: patients (n = 4) undergoing echocardiography during open heart surgery and intracardiac echocardiography (ICE) during catheter ablation of atrial fibrillation (n = 5). RESULTS: Group 1: The left main coronary artery was found to be 3.8 +/- 1.2 mm from the right ventricular outflow tract in patients undergoing ablation. Group 2: The minimum distance between the left main, left anterior descending, and right coronary artery to the RV outflow tract endocardial wall were 4.1 +/- 1.9 mm, 2.0 +/- 0.6 mm, and 4.3 +/- 1.9 mm (average +/- SD) respectively. Group 3: During open heart surgery using echocardiography, the minimum distance between the left main and the right coronary artery to the RV outflow tract were 3.4 +/- 0.35 mm and 2.0 +/- 0.1 mm, respectively. The distance between the let main coronary artery and the RVOT by ICE was 3.8 +/- 0.45 mm. CONCLUSIONS: The major coronary arteries lie in close proximity of the RVOT, and their anatomic course should be taken into consideration during ablation of ventricular tachycardias arising from the RV outflow tract.

Adult↗
PubMed2005

Impedance monitoring during catheter ablation of atrial fibrillation.

BACKGROUND: Delivery of radiofrequency energy in proximity of a pulmonary vein can cause vein stenosis. A sudden decrease in impedance as the catheter is moved from the vein into the left atrium (LA) has been used to define the pulmonary vein-LA transition during ablation procedures. OBJECTIVES: The purpose of this study was to define the variables affecting impedance measurement. METHODS: In vitro analysis of impedance was performed in a saline bath using sheaths and a plastic stereolithographic model of the LA. Impedance was continuously monitored during a calibrated pullback from the pulmonary vein into the LA in 37 veins of 10 patients referred for catheter ablation. Location of the catheter was confirmed by the following imaging modalities: intracardiac echocardiography, contrast venography, electroanatomic mapping, and computed tomography/magnetic resonance imaging (offline) in all patients. RESULTS: Larger cross-sectional areas containing the catheter correlated with lower impedance in an exponential manner both with respect to sheath size (R(2) = 0.99) and in the stereolithographic model (R(2) = 0.91). In vivo, the impedance in the pulmonary veins decreased in an exponential manner as the catheter was pulled back into the LA. However, impedance at the vein orifice was not significantly higher than the LA. A defined cutoff value for defining the pulmonary vein-LA transition could not be identified. CONCLUSION: The primary determinant of impedance is the cross-sectional area of the space containing the catheter. Impedance monitoring alone does not guarantee a catheter tip position outside the pulmonary vein. Intraprocedural imaging confirmation should be considered to avoid radiofrequency application within pulmonary veins.

Aged↗
PubMed2005

Beyond coronary sinus angiography: the value of coronary arteriography and identification of the pericardiophrenic vein during left ventricular lead placement.

OBJECTIVE: The purpose of this study was to define the role coronary arteriography (venous phase) for improving the success of left ventricular (LV) lead implantation and to define the value of identifying the pericardiophrenic vein for optimal LV lead placement in biventricular (bi-v) device implantation. METHODS: Seventy-seven patients underwent bi-v device implantation between July 2002 and October 2003. If the coronary sinus (CS) could not be accessed, then left coronary arteriography was performed during the same procedure. CS access was guided by venous phase images of the coronary arteriogram. The pericardiophrenic vein was identified by selective cannulation or direct visualization. Patients with Cr > 1.5 had gadolinium used as the contrast agent. RESULTS: Seventy-five successful implants were performed (97%). In seven patients (9%) repeated attempts at retrograde cannulation of the CS failed (attempt time 130 +/- 20 minute, mean +/- SD). In these patients, coronary arteriography helped define the location of the CS, which was subsequently successfully cannulated. In six patients the pericardiophrenic vein was identified either during occlusion venography of the CS (postthoracotomy, veno-venous collaterals, n = 2) or during selective cannulation of the pericardiophrenic vein (using a DAIG Csl catheter, n = 4). The vein was directly visualized in three patients who underwent surgical LV lead implantation. LV leads in all these cases were implanted in areas not overlying the preidentified pericardiophrenic vein. During follow-up, none of these patients had evidence of phrenic nerve stimulation. CONCLUSIONS: Intraoperative left coronary arteriography increases the success of CS cannulation. Identification of the pericardiophrenic vein is a useful method to avoid phrenic nerve stimulation.

Contrast Media↗
PubMed2003

Minimally invasive orbital decompression for Graves' ophthalmopathy.

We reviewed a 7-year experience at a tertiary-care, academic medical center with balanced, minimally invasive decompression for Graves' ophthalmopathy, in an effort to define the goals, risks, and outcomes of surgical intervention. Endoscopic medial decompression was performed in 26 patients; 23 underwent lateral decompression as well, and 13 also had inferior decompression. Septoplasty, turbinate reduction, and orbital rim augmentation were performed as needed. The indications for surgery were threat to vision (n = 10) and proptosis with a desire to return to the predisease state (rehabilitative, n = 16). The exophthalmos improved by a mean of 4.4 mm (p < .001). All patients who had surgery for threatened vision had improved vision after the operation. There were 3 patients with new-onset postoperative diplopia, 2 of whom underwent strabismus surgery. There was 1 case of postoperative sinusitis, which resolved with oral antibiotics and nasal decongestion, and 1 case of transient ulnar neuropathy. There were no other intraoperative or postoperative complications. Modern methods of orbital decompression provide a minimally invasive, effective, and relatively safe approach to the treatment of Graves' ophthalmopathy.

Adult↗