Multifactorial QT interval prolongation

Acquired long QT interval has been widely reported to be a consequence of drug therapy and electrolyte disturbances. We describe two cases of multifactorial acquired QT interval prolongation and torsades de pointes. In the first case, the drugs venlafaxine, amiodarone and domperidone may have contributed to QT interval prolongation in a patient with hypokalemia and hypomagnesaemia. In the second case, QT interval prolongation occurred in a patient taking quetiapine and citalopram, and whose use of hydrocholorothiazide and history of chronic alcohol abuse likely contributed by rendering the patient hypokalemic. These cases highlight the potential risks associated with polypharmacy and demonstrate that though torsades de pointes is an uncommon arrhythmia, the combination of multiple factors known to prolong QT interval may precipitate this life-threatening arrhythmia. (Cardiol J 2010; 17, 2: 184-188

Risk Score, Causes, and Clinical Impact of Failure of Transradial Approach for Percutaneous Coronary Interventions

ObjectivesTo study the causes of and to develop a risk score for failure of transradial approach (TRA) for percutaneous coronary intervention (PCI).BackgroundTRA-PCI failure has been reported in 5% to 10% of cases.MethodsTRA-PCI failure was categorized as primary (clinical reasons) or crossover failure. Multivariate analysis was performed to determine independent predictors of TRA-PCI failure, and an integer risk score was developed.ResultsFrom January to June 2010, TRA-PCI was attempted in 1,609 (97.3%) consecutive patients, whereas 45 (2.7%) had primary TRA-PCI failure. Crossover TRA-PCI failure occurred in 30 (1.8%) patients. Causes of primary TRA-PCI failure included chronic radial artery occlusion (11%), previous coronary artery bypass graft (27%), and cardiogenic shock (20%). Causes for crossover TRA-PCI failure included: inadequate puncture in 17 patients (57%); radial artery spasm in 5 (17%); radial loop in 4 (13%); subclavian tortuosity in 2 (7%); and inadequate guide catheter support in 2 (7%) patients. Female sex (odds ratio [OR]: 3.2; 95% confidence interval [CI]: 1.95 to 5.26, p < 0.0001), previous coronary artery bypass graft (OR: 6.1; 95% CI: 3.63 to 10.05, p < 0.0001), and cardiogenic shock (OR: 11.2; 95% CI: 2.78 to 41.2, p = 0.0011) were independent predictors of TRA-PCI failure. Risk score values from 0 to 7 predicted a TRA-PCI failure rate from 2% to 80%.ConclusionsIn a high-volume radial center, 2.7% of patients undergoing PCI are excluded from initial TRA on clinical grounds, whereas crossover to femoral approach is required in only 1.8% of the cases. A new simple clinical risk score is developed to predict TRA-PCI failure

Relation of mitral valve morphology and motion to mitral regurgitation severity in patients with mitral valve prolapse

<p>Abstract</p> <p>Background</p> <p>Mitral valve thickness is used as a criterion to distinguish the classical from the non-classical form of mitral valve prolapse (MVP). Classical form of MVP has been associated with higher risk of mitral regurgitation (MR) and concomitant complications. We sought to determine the relation of mitral valve morphology and motion to mitral regurgitation severity in patients with MVP.</p> <p>Methods</p> <p>We prospectively analyzed transthoracic echocardiograms of 38 consecutive patients with MVP and various degrees of MR. In the parasternal long-axis view, leaflets length, diastolic leaflet thickness, prolapsing depth, billowing area and non-coaptation distance between both leaflets were measured.</p> <p>Results</p> <p>Twenty patients (53%) and 18 patients (47%) were identified as having moderate to severe and mild MR respectively (ERO = 45 ± 27 mm²vs. 5 ± 7 mm², p < 0.001). Diastolic leaflet thickness was similar in both groups (5.5 ± 0.9 mm vs. 5.3 ± 1 mm, p = 0.57). On multivariate analysis, the non-coaptation distance (OR 7.9 per 1 mm increase; 95% CI 1.72-37.2) was associated with significant MR. Thick mitral valve leaflet as traditionally reported (≥ 5 mm) was not associated with significant MR (OR 0.9; 95% CI 0.2-3.4).</p> <p>Conclusions</p> <p>In patients with MVP, thick mitral leaflet is not associated with significant MR. Leaflet thickness is probably not as important in risk stratification as previously reported in patients with MVP. Other anatomical and geometrical features of the mitral valve apparatus area appear to be much more closely related to MR severity.</p

Treatment of functional mitral valve regurgitation with the permanent percutaneous transvenous mitral annuloplasty system: Results of the multicenter international Percutaneous Transvenous Mitral Annuloplasty System to Reduce Mitral Valve Regurgitation in Patients with Heart Failure trial

Objectives PTOLEMY-2 was a prospective multicenter phase I single-arm feasibility trial to evaluate the second-generation permanent percutaneous transvenous mitral annuloplasty (PTMA) device in reducing functional mitral regurgitation (MR). Background Percutaneous MR reduction has been performed through a direct method of clipping and securing the mitral leaflets together or an indirect approach of reducing mitral annular dimension via the coronary sinus. The PTMA device is the only coronary sinus mitral repair device without a static fixation element. Methods Patients with at least moderate functional MR, New York Heart Association functional class II to IV, and left ventricular ejection fraction of 20% to 50% were enrolled at 14 centers in 5 countries. Device effects on patients were assessed by serial echocardiography, quality of life (QOL), and exercise capacity metrics. Results A total of 43 patients were recruited, and 30 patients (70%) were implanted with a permanent PTMA device with a mean follow-up of 5.8 +/- 3.8 months. The primary safety end point (freedom from death, myocardial infarction, stroke, or emergency surgery) at 30 days was met in 28 patients, whereas 2 patients died of device-related complications. The primary efficacy end point (MR reduction of at least 1.0 grade or reduction of regurgitant orifice area by 0.1 cm(2) or regurgitant volume by 1 Conclusions Overall, PTMA had mild impact on MR reduction, left ventricular remodeling, QOL, and exercise capacity. During follow-up, the risk/benefit ratio remained suboptimal. (Am Heart J 2013;165:761-9.