Nani Osada

Endovascular suture versus cutdown for endovascular aneurysm repair: a prospective randomized pilot study

PURPOSE To evaluate safety and cost benefits of the percutaneous technique for treatment of aortic aneurysm, a prospective randomized study was performed that compared the endovascular suture technique with conventional cutdown access and repair. MATERIALS AND METHODS From January 2002 through July 2002, 30 endografts, including 14 Talent stent-grafts (Medtronic, Sunrise, Fla) and 16 Zenith endografts (Cook, Bloomington, Ind) were implanted in 30 patients for endovascular aneurysm treatment. The patients were randomized to either percutaneous technique (group A) or conventional cutdown (group B). Fifty-five femoral arteries were cannulated with large-bore (14F-25F) introducers and were included in the study. Safety and efficiency of both techniques were assessed by recording the complication rates, operation time, discharge, and time to ambulation. Comparison of selected estimated costs included both variable and fixed costs for femoral access and expenses for treatment of complications. RESULTS No operative deaths occurred. The complication rates were similar and included 1 arterial thrombosis in each group, 3 lymphoceles in group B, and 1 conversion to cutdown because of bleeding in group A. Mean surgery time (86.7 +/- 27 minutes vs 107.8 +/- 38.5 minutes; P <.05) and time to ambulation (20.1 +/- 4.3 hours vs 33.1 +/- 18.4 hours; P <.001) were significantly shorter in the group treated percutaneously. Because of the cost of the closure device, total cost of the percutaneous technique averaged 99.2 euro; more than cutdown. CONCLUSIONS The percutaneous technique decreases the invasiveness of endovascular therapy of aortic aneurysm and reduces operative time and time to ambulation. Complications were roughly equivalent in severity. The additional cost for the device appears to justify its use for this form of aneurysm treatment.

Inhibition of the Na+/Ca2+ exchanger suppresses torsades de pointes in an intact heart model of long QT syndrome-2 and long QT syndrome-3.

BACKGROUND Long QT syndrome (LQTS) is associated with sudden cardiac death resulting from torsades de pointes (TdP), which are triggered by early afterdepolarizations (EADs). The cardiac Na(+)/Ca(2+) exchanger (NCX) has been suggested to work as a trigger for EADs. OBJECTIVE The purpose of this study was to test the hypothesis that inhibition of NCX with a newly developed selective NCX inhibitor (SEA0400) reduces TdP. METHODS AND RESULTS In 34 Langendorff-perfused rabbit hearts, the I(Kr)-blocker sotalol (100 microM; n = 18) as well as veratridine (0.5 microM; n = 16), an inhibitor of sodium channel inactivation, led to a significant increase in monophasic action potential (MAP) duration thereby mimicking LQTS2 and LQTS3. In bradycardic hearts, recordings of eight MAPs demonstrated an increased dispersion of repolarization (sotalol: 67%; veratridine: 89%; P <.05). After lowering of potassium concentration, sotalol (56%) and veratridine (63%) induced TdP. Perfusion with SEA0400 (1 microM) suppressed EADs in 15 of 16 sotalol hearts and in seven of 13 veratridine hearts. SEA0400 significantly shortened MAP duration and reduced dispersion of repolarization in both groups (P <.05). This reduced TdP incidence in the sotalol group (100%) and in the veratridine group (77%). To investigate the effects of NCX inhibition on the cellular level, we used a computer model of the rabbit ventricular myocyte. I(Na) and I(Kr) were modified to mimic the effects of veratridine and sotalol, respectively. Consistent with our in vitro experiments, reduction of NCX activity accelerated repolarization of the cellular action potential and prevented EADs. CONCLUSION In an intact rabbit heart model of LQT2 and LQT3 as well as in a computer model of the rabbit cardiac myocyte, inhibition of NCX is effective in preventing TdP due to a suppression of EADs, a reversion of action potential prolongation, and a reduction of dispersion of repolarization. Our observations suggest a therapeutic benefit of selective NCX inhibition in LQTS.

Reduction of dispersion of repolarization and prolongation of postrepolarization refractoriness explain the antiarrhythmic effects of quinidine in a model of short QT syndrome.

Background: Short QT syndrome (SQTS) is a newly described ion channelopathy, characterized by a short QT interval resulting from an accelerated cardiac repolarization, associated with syncope, atrial fibrillation, and sudden cardiac death due to ventricular fibrillation. As therapeutic options in SQTS are still controversial, we examined antiarrhythmic mechanisms in an experimental model of SQTS.

Comparison of the in vitro electrophysiologic and proarrhythmic effects of amiodarone and sotalol in a rabbit model of acute atrioventricular block

The mechanisms for the different proarrhythmic potential of antiarrhythmic drugs in the presence of comparable QT prolongation are not completely understood. The reasons for the lower proarrhythmic potential of amiodarone as compared with other class-III antiarrhythmic drugs such as sotalol, a fact that has been well established for years, is insufficiently known. Therefore, the aim of our study was to assess the different electrophysiologic effects of amiodarone and sotalol in a previously developed experimental model of proarrhythmia. In eight male rabbits, amiodarone (280–340 mg/d) was fed over a period of six weeks. Hearts were excised and retrogradely perfused. Up to eight simultaneous epi- and endocardial monophasic action potentials (MAP) were recorded. Results were compared with sotalol-treated (10-50-100 μM) hearts (n = 13). Amiodarone and sotalol (50 μM and 100 μM) led to a significant increase in QT interval (mean increase: amiodarone: 31 ± 6 ms; sotalol: 41 ± 4 ms and 61 ± 9 ms) and MAP-duration (mean increase-MAP90: amiodarone: 20 ± 5 ms; sotalol: 17 ± 5 ms and 25 ± 8 ms) (P < 0.01). In bradycardic (AV-blocked) hearts, MAP-recordings demonstrated reverse-use dependence and a significant increase in dispersion of repolarization (MAP90) in the presence of sotalol (P < 0.01), but not in amiodarone-treated hearts (10%; p = ns). Sotalol led to early afterdepolarizations (EAD) and torsade de pointes (TdP) after lowering of potassium concentration (6 of 13 hearts). In amiodarone-treated, hypokalemic hearts, no EAD or TdP occurred. Sotalol changed the MAP configuration to a triangular pattern (ratio-MAP90/50: 1.52 as compared with 1.36 at baseline) whereas amiodarone caused a rectangular pattern of MAP prolongation (ratio-MAP90/50: 1.36). In conclusion, these results show no direct correlation between the occurrence of TdP and the degree of QT prolongation. Several factors including reverse-use dependence, dispersion of repolarization, and the propensity to induce early afterdepolarizations but also differences in the action potential configuration may help to understand proarrhythmic side effects of drugs.

The addition of voice prompts to audiovisual feedback and debriefing does not modify CPR quality or outcomes in out of hospital cardiac arrest--a prospective, randomized trial.

AIMS Chest compression quality is a determinant of survival from out-of-hospital cardiac arrest (OHCA). ERC 2005 guidelines recommend the use of technical devices to support rescuers giving compressions. This prospective randomized study reviewed influence of different feedback configurations on survival and compression quality. MATERIALS AND METHODS 312 patients suffering an OHCA were randomly allocated to two different feedback configurations. In the limited feedback group a metronome and visual feedback was used. In the extended feedback group voice prompts were added. A training program was completed prior to implementation, performance debriefing was conducted throughout the study. RESULTS Survival did not differ between the extended and limited feedback groups (47.8% vs 43.9%, p = 0.49). Average compression depth (mean ± SD: 4.74 ± 0.86 cm vs 4.84 ± 0.93 cm, p = 0.31) was similar in both groups. There were no differences in compression rate (103 ± 7 vs 102 ± 5 min(-1), p=0.74) or hands-off fraction (16.16% ± 0.07 to 17.04% ± 0.07, p = 0.38). Bystander CPR, public arrest location, presenting rhythm and chest compression depth were predictors of short term survival (ROSC to ED). CONCLUSIONS Even limited CPR-feedback combined with training and ongoing debriefing leads to high chest compression quality. Bystander CPR, location, rhythm and chest compression depth are determinants of survival from out of hospital cardiac arrest. Addition of voice prompts does neither modify CPR quality nor outcome in OHCA. CC depth significantly influences survival and therefore more focus should be put on correct delivery. Further studies are needed to examine the best configuration of feedback to improve CPR quality and survival. REGISTRATION ClinicalTrials.gov (NCT00449969), http://www.clinicalTrials.gov.

Early Outcomes for Fenestrated and Chimney Endografts in the Treatment of Pararenal Aortic Pathologies Are Not Significantly Different: A Systematic Review With Pooled Data Analysis

Purpose To compare short-term outcomes between fenestrated and chimney endografts for pararenal aortic pathologies. Methods An English-language literature search up to January 2012 found 129 articles evaluating the immediate outcomes of endovascular repair of degenerative juxta-/suprarenal aortic aneurysms, type I endoleaks, and para-anastomotic aneurysms using the chimney technique or fenestrated endografts. Data concerning thoracoabdominal aortic aneurysms, ruptured aneurysms, and reports with <5 cases were excluded (n=84). An additional 28 articles were excluded for insufficient data, leaving 17 articles for review: 5 dealing with chimney grafts in 123 patients with pararenal aortic pathologies and 12 presenting data on 631 patients undergoing fenestrated stent-grafting. The composite endpoints were 30-day mortality, deterioration of renal function, new postoperative dialysis dependence, and endoleak rate. Results Cumulative 30-day procedure-related mortality was 0.58% (95% CI 0.0% to 2.93%) for the chimney group (n=3) and 1.17% (95% CI 0.26% to 2.09%, p=0.645) for the f-EVAR group (n=9). In the f-EVAR group, 86 (9.67%;95% CI 4.77% to 14.57%) patients suffered from postoperative renal impairment vs. 16 (12.43%) patients in the chimney group (95% CI 2.39% to 22.48%, p=0.628). In the chimney group, 4 (0.57%;95% CI 0.0% to 2.94%) patients required persistent postoperative dialysis in contrast to the 1.33% (95% CI 0.29% to 2.37%, p=0.567) rate (n=9) in patients undergoing f-EVAR. There were also no significant differences recorded in the endoleak rate: 1.93% (95% CI 0.0% to 4.82%) of the chimney patients had a persistent type Ia endoleak vs. 2.06% (95% CI 0.69% to 3.43%) for the f-EVAR group (p=0.939). For type II endoleaks, the rates were 2.16% (95% CI 0.0% to 10.77%) for the chimney group vs. 6.88% (95% CI 1.92% to 11.83%) for the f-EVAR group (p=0.352). No patient in the chimney group had a type III endoleak, and the rate was low in the f-EVAR group (0.32%,95% CI 0.0% to 0.91%, p=0.079). Conclusion No statistically significant differences were found between the two endovascular approaches for pararenal aortic pathologies in terms of 30-day mortality, renal impairment, or endoleak. These findings support the assumption that chimney grafts may be a reliable alternative in the treatment of pararenal aortic pathologies.

Proarrhythmia as a Class Effect of Quinolones: Increased Dispersion of Repolarization and Triangulation of Action Potential Predict Torsades de Pointes

Background: Numerous noncardiovascular drugs prolong repolarization and thereby increase the risk for patients to develop life‐threatening tachyarrhythmias of the torsade de pointes (TdP) type. The development of TdP is an individual, patient‐specific response to a repolarization‐prolonging drug, depending on the repolarization reserve. The aim of the present study was to analyze the underlying mechanisms that discriminate hearts that will develop TdP from hearts that will not develop TdP. We therefore investigated the group of quinolone antibiotics that reduce repolarization reserve via IKr blockade in an intact heart model of proarrhythmia.

A new mechanism preventing proarrhythmia in chronic heart failure: rapid phase-III repolarization explains the low proarrhythmic potential of amiodarone in contrast to sotalol in a model of pacing-induced heart failure.

Life‐threatening arrhythmias are a major problem in chronic heart failure (CHF). The aim of the present study was to investigate the mechanism underlying the low proarrhythmic potential of amiodarone in a model of pacing‐induced heart failure.

Verapamil prevents torsade de pointes by reduction of transmural dispersion of repolarization and suppression of early afterdepolarizations in an intact heart model of LQT3

AbstractBackgroundIn long QT syndrome (LQTS), prolongation of the QT–interval is associated with sudden cardiac death resulting from potentially life–threatening polymorphic tachycardia of the torsade de pointes (TdP) type. Experimental as well as clinical reports support the hypothesis that calcium channel blockers such as verapamil may be an appropriate therapeutic approach in LQTS. We investigated the electrophysiologic mechanism by which verapamil suppresses TdP, in a recently developed intact heart model of LQT3.Methods and results In 8 Langendorff–perfused rabbit hearts, veratridine (0.1 µM), an inhibitor of sodium channel inactivation, led to a marked increase in QT–interval and simultaneously recorded monophasic ventricular action potentials (MAPs) (p < 0.05) thereby mimicking LQT3. In bradycardic (AV–blocked) hearts, simultaneous recording of up to eight epi– and endocardial MAPs demonstrated a significant increase in total dispersion of repolarization (56%, p < 0.05) and reverse frequency–dependence. After lowering potassium concentration, veratridine reproducibly led to early afterdepolarizations (EADs) and TdP in 6 of 8 (75%) hearts. Additional infusion of verapamil (0.75 µM) suppressed EADs and consecutively TdP in all hearts. Verapamil significantly shortened endocardial but not epicardial MAPs which resulted in significant reduction of ventricular transmural dispersion of repolarization.ConclusionsVerapamil is highly effective in preventing TdP via shortening of endocardial MAPs, reduction of left ventricular transmural dispersion of repolarization and suppression of EADs in an intact heart model of LQT3. These data suggest a possible therapeutic role of verapamil in the treatment of LQT3 patients.

Gender differences in chronic pruritus: women present different morbidity, more scratch lesions and higher burden

Although sex and gender are increasingly perceived as important factors in medicine, there is only very little knowledge on these issues in patients with chronic pruritus (CP).