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Jamshid Alaeddini

Publications and source records attributed to Jamshid Alaeddini.

11 recordsLinked to original sources
PubMed2006

Incidence, time course, and characteristics of microbubble formation during radiofrequency ablation of pulmonary veins with an 8-mm ablation catheter.

BACKGROUND: Microbubble formation during pulmonary vein (PV) radiofrequency (RF) ablation of atrial fibrillation (AF) occurs relatively frequently. Prior studies have shown that microbubble formation may be associated with an increased risk of complications. However, the incidence, time course, and temperature characteristics of microbubble formation during AF ablation with an 8-mm catheter have not been prospectively described in humans. METHODS: We studied 46 (30 men, age 56+/-10 years) patients with AF who underwent RF ablation of PVs between January 2005 and December 2005 using an 8F, 8-mm Biosensetrade mark ablation catheter (Biosense-Webster, Diamond Bar, CA, USA). All patients underwent continuous intracardiac echocardiography (ICE). Microbubble patterns were classified as either type 1 (intermittent, scattered microbubble formation) or type 2 (explosive shower of dense microbubbles). Formation of any microbubbles was detected by ICE and the time, PV location, and electrode temperature were recorded. RESULT: A total of 1,479 (32+/-13, range 12-73) RF lesions were delivered to 167 veins. Twenty (2%) lesions were classified as type 2. Since the number of lesions resulting in type 2 bubbles was very small, only type 1 lesions were included in the final analysis. Thirty-nine (85%) patients had at least one lesion associated with bubble formation during ablation (mean: 7+/-7 lesions, range 1-28 lesions). Twenty-three percent (327) of the RF lesions resulted in bubble formation. RF generator power setting during lesions resulting in bubble formation was lower than lesions which did not result in bubble formation (47.9+/-7.4 W vs 49.7+/-7.1 W, P<0.001). Logistic regression analysis revealed a significant negative correlation (P<0.001) between RF generator power settings and a positive correlation between the generator temperature settings and formation of bubbles (both P<0.02). However, the maximum temperature attained was not different between lesions resulting in bubble formation (n=327) and those which did not result in bubble formation (n=1,139). Fifty-three (16%) of the lesions associated with bubble formation occurred within 2-10 seconds after RF was begun. Bubble formation was significantly more frequent in left superior PVs compared to the other PVs (left superior PV 27.3% left inferior PV 18.6%, right superior PV 20.5%, and right inferior PV 18.8%, P=0.005, left superior PV vs other PVs, P<0.001) even after adjustment for the other factors including generator power settings and the temperature setting. CONCLUSION: Bubble formation is common during RF ablation of PV with 8-mm tip catheter and can occur as early as 2 seconds after starting RF. RF generator power is negatively correlated with bubble formation while generator temperature settings are positively correlated with formation of bubbles. Microbubble formation is also more frequent with ablation of the left superior PV probably due to better catheter contact in that area.

Atrial Fibrillation↗
PubMed2006

Frequency of atrial tachyarrhythmias following transcatheter closure of patent foramen ovale.

BACKGROUND: Transcatheter closure of patent foramen ovale (PFO) in patients with a history of cryptogenic stroke is performed with increasing frequency. However, the long-term effects of these closure devices on atrial tachyarrhythmias (ATs) are not known. METHODS AND RESULTS: The study population included 71 patients [31 (44%) men, aged 54 +/- 14 years] with PFO, diagnosed by transesophageal echocardiography (TEE), and greater than or equal to 1 cryptogenic stroke (n = 70) or orthodoxia (n = 1). Patients underwent transcatheter closure of PFO using a 28 mm (n = 53) or a 33 mm (n = 18) CardioSEAL closure device (n = 67) or an Amplatzer occluder (n = 4). Five (7%) patients presented with newly diagnosed (n = 4) or recurrent (n = 1) episodes of AT (3 atrial fibrillation and 2 typical atrial flutter) within 1 to 480 days following the procedure, with an average time to onset of 175 +/- 221 days. ATs were more frequent in those who received a 33 mm device than those who received a 28 mm device [4/18 (22%) vs. 1/53 (2%); p < 0.05]. Patients with ATs showed a trend toward a larger left atrium only on apical view (6.5 +/- 1.4 cm vs. 5.1 +/- 0.9 cm; p = 0.05). However, the difference in left atrial size on parasternal view and right atrial size between the 2 groups was not statistically significant (4.5 +/- 1.1 cm vs. 3.7 +/- 0.8 cm and 5.9 +/- 2.4 cm vs. 4.6 +/- 0.7 cm). Conclusion. Compared to the age-matched population, sustained ATs appear to be relatively common following transcatheter closure of PFO. In our series, they seemed to occur more frequently in patients who received larger devices.

Adult↗
PubMed2005

Repeated dual external direct cardioversions using two simultaneous 360-J shocks for refractory atrial fibrillation are safe and effective.

Failure of cardioversion of atrial fibrillation (AF) to sinus rhythm (SR) by standard external direct current cardioversion (DCC) may be due to failure of delivery of enough defibrillating energy rather than to the true refractoriness of AF. Ninety-nine patients with persistent AF (76 male; age 63.7 +/- 0.4 years; weight 113.1 +/- 25.1 kg) who failed standard DCC were included in this report. Under anesthesia, QRS synchronous shocks were delivered across anteroposterior electrodes in the following sequence: (1) a single 360-J shock; (2) another single 360-J shock within 2 minutes; (3) 30 minutes of rest, reinduction of anesthesia and delivery of two simultaneous monophasic 360-J shocks. All patients underwent all three DCC steps. Sixty-six (67%) patients converted to SR following the first dual simultaneous shock. Fourteen patients (14%) required more than one dual shock to achieve SR. This increased the overall success rate of resuming SR to 81%. Except for minor skin burns in three patients there were no procedure related complications. On follow-up at 1 month, 55 (56%) patients were still in SR, whereas 50 (51%) patients maintained SR at 12 months. This was similar to our general DCC population (55% of the 1698 patients were in SR 6 months post-DCC, P = ns). In conclusion, dual external monophasic 360-J DCC is an effective rescue technique for restoration of SR in patients with AF refractory to standard DCC. AF in these patients seems to be as amenable to chronic suppression as AF in the general population of DCC patients.

Adult↗
PubMed2004

Efficacy and safety of sildenafil in the evaluation of pulmonary hypertension in severe heart failure.

This study sought to evaluate the utility of sildenafil in assessing pulmonary artery reactivity in left-sided cardiac failure and secondary pulmonary hypertension (PH). Fourteen consecutive patients with heart failure were studied, with oral doses of either sildenafil 25 mg (n = 8) or 50 mg (n = 6) every 8 hours for </=3 doses, and invasive serial hemodynamic measurements were performed. Thirteen patients (93%) demonstrated >20% decreases in pulmonary artery pressures. There was also a 20% reduction of the pulmonary vascular resistance/systemic vascular resistance ratio, indicating relative pulmonary artery selectivity. Compared with sildenafil 25 mg, sildenafil 50 mg demonstrated greater reductions of pulmonary pressures. Oral sildenafil is safe and effective for the evaluation of PH reactivity in heart failure.

Administration, Oral↗
PubMedDate not supplied

Use of pharmaceuticals in noninvasive cardiovascular diagnosis.

A number of pharmaceuticals are employed as diagnostic agents for cardiovascular diseases. Four groups of agents are reviewed here: 1) vasoactive substances employed as adjuncts to physical maneuvers in diagnosis of structural heart disease; 2) vasodilators used to produce heterogeneity of coronary flow; 3) sympathomimetic agents simulating the effects of exercise on the heart for the purpose of detection of coronary artery stenosis; and 4) ultrasonic contrast agents used to enhance myocardial imaging for the assessment of segmental wall motion. In the first group are amyl nitrate, a vasodilator, and methoxamine and phenylephrine, both vasopressors. The vasodilators of the second group are dipyridamole and adenosine. When combined with scintigraphic perfusion imaging or with echocardiographic assessment of segmental wall motion, these agents can detect single- or multiple-vessel coronary artery disease with sensitivity and specificity comparable to submaximal exercise. They are especially useful for preoperative risk assessment before noncardiac surgery. The sympathomimetic agents of the third group, dobutamine and arbutamine, increase myocardial contractility and heart rate, and dilate the peripheral vasculature. As with the vasodilators, when combined with nuclear or echocardiographic techniques they are equivalent to exercise in detection of coronary disease. They are especially useful in patients with bronchospastic disease and for assessment of myocardial viability. Agents from groups 2 and 3 have acceptable side-effect and safety profiles. The last group reviewed includes echocardiographic contrast agents that, in this investigative setting, are employed to enhance detection of segmental wall motion when used with agents from groups 2 and 3.

Cardiovascular Diseases↗
PubMedDate not supplied

Sildenafil and assessment of pulmonary arterial reactivity in heart failure.

Pulmonary hypertension is a daunting accompaniment of advanced heart failure. Efforts to safely and consistently lower pulmonary vascular resistance are necessary but fraught with challenges. In this report the authors explore the novel use of sildenafil, an inhibitor of phosphodiesterase-5, in tackling pulmonary hypertension in heart failure. The salutary effects of this agent deserve further study.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMedDate not supplied

Difficult cases in heart failure. Percutaneous transluminal septal myocardial ablation in the management of hypertrophic obstructive cardiomyopathy.

Hypertrophic cardiomyopathy is a complex genetic condition with a heterogeneous clinical course. Some patients remain asymptomatic throughout life while others develop one or more of the adverse clinical consequences including symptoms of congestive heart failure with exertional dyspnea and functional disability (usually with preserved left ventricular systolic function), atrial fibrillation, or sudden cardiac death. Because of this heterogenicity in the clinical presentations, management of patients with hypertrophic cardiomyopathy includes a wide range of pharmacologic therapies as well as invasive approaches. In recent years, nonsurgical catheter-based treatment of hypertrophic cardiomyopathy has been increasingly used in the management of a subset of these patients. The authors present a case of percutaneous transluminal septal myocardial ablation in a patient with hypertrophic cardiomyopathy who was symptomatic despite maximal medical treatment.

Atrial Fibrillation↗