Slittable sheath supported right ventricular pacing lead implantation in persistent left superior vena cava with absent right superior vena cava: a case report.

BACKGROUND: Persistent left superior vena cava (PLSVC) is the most common variant of systemic venous drainage. In the absence of the right superior vena cava (RSVC), implantation of a right ventricular pacing lead may be challenging. Therefore specific implantation techniques and experiences in PLSVC are worth reporting. CASE PRESENTATION: We present a case report of a 90-year-old Caucasian female patient with PLSVC during single chamber pacemaker implantation due to the third-degree atrioventricular block. With common implantation techniques, we did not even reach the right ventricle. Therefore slittable CPS Direct ™ Universal sheath was employed to overcome the acute angle from PLSVC to tricuspid valve and ensure more fixation stability for longer 100-cm right ventricular lead placement. CONCLUSION: This case demonstrates safe implantation of 100-cm long right ventricular bipolar active fixation pacing lead using common slittable CPS Direct ™ Universal sheath after failed attempts with "C" and "J" stylet shaped electrode. This sheath provides different angle towards tricuspid valve and more fixation stability in patient with PLSVC and absent connection to right atrium.

Cardiac Strains As a Tool for Optimization of Cardiac Resynchronization Therapy in Non-responders: a Pilot Study.

BACKGROUND: Approximately 30% of patients do not respond to implantation of Cardiac Resynchronization Therapy - Defibrillators (CRT-D). The aim of this study was to investigate the potential for cardiac strain speckle tracking to optimize the performance of CRT-D in non-responding patients. METHODS: 30 patients not responding to Cardiac Resynchronization Therapy-Defibrillators after 3 months were randomly divided into control and intervention groups. Atrioventricular interval was adjusted so that E and A waves did not overlap, the interventricular interval was subsequently optimized to yield maximum improvement of the sum of longitudinal+radial+circumferential strains. The left ventricular ejection fraction (LVEF) and NYHA improvement 3 months after optimization were evaluated and use of other strain combinations assessed. RESULTS: A significant correlation between the (combined) strain change and LVEF improvement was detected (p<0.01). 75% of patients with non-ischemic etiology of heart failure who did not respond to the original CRT-D reacted favorably with significant LVEF and NYHA improvement. The area strain was the best predictor of LVEF/NYHA improvement in those patients. No significant improvement was recorded in patients with ischemic etiology. CONCLUSIONS: AV and VV optimization based on speckle tracking is a very promising method potentially leading to a significant improvement of the outcome of CRT-D, especially in patients with non-ischemic etiology of heart failure.

Comparison of different methods of ABI acquisition for detection of peripheral artery disease in diabetic patients.

BACKGROUND: Ankle brachial index (ABI) is the principal screening method for peripheral arterial disease (PAD). In this study, we compare various types of Doppler-derived and oscillometric ABIs with results obtained through duplex ultrasonography. METHODS: 62 patients were enrolled in the study. For each limb, blood pressures for both ankle arteries and the arm were measured using Doppler and an automated oscillometric device. Duplex ultrasound was performed for all limbs and occlusions >50% were considered PAD-positive. ABI was calculated using both higher (HABP) and lower (LABP) arterial blood pressure on the individual limbs and the ability to predict duplex-detected stenoses was evaluated. RESULTS: LABP calculation provided results superior to the guideline-recommended HABP. Considering patients with ABI >1.4 or measurement failure as PAD-positive further enhanced the test parameters. The higher ABI cut-off of 1.0 resulted in somewhat better sensitivities (max 92%) and negative predictive values (max 87%) at the expense of a substantial increase in the number of false positives. Oscillometric method yielded poor sensitivities but very good specificities (max 94%) and positive predictive values (max 90%). CONCLUSIONS: Doppler-based LABP provides better results than the guideline-recommended HABP in diabetic patients, nevertheless even this method is not perfect. Increasing the cut-off value to 1.0 in these patients does not bring a substantial improvement of the test performance. Patients with high ABI should be automatically considered PAD-positive and referred for further investigation using imaging techniques.