Association of pre-left ventricular assist device defibrillator shocks for ventricular arrhythmia with clinical outcomes after left ventricular assist device implantation.

Background: Implantable cardioverter-defibrillation (ICD) shocks after left ventricular assist device therapy (LVAD) are associated with adverse clinical outcomes. Little is known about the association of pre-LVAD ICD shocks on post-LVAD clinical outcomes and whether LVAD therapy affects the prevalence of ICD shocks. Objectives: The purpose of this study was to determine whether pre-LVAD ICD shocks are associated with adverse clinical outcomes post-LVAD and to compare the prevalence of ICD shocks before and after LVAD therapy. Methods: Patients 18 years or older with continuous-flow LVADs and ICDs were retrospectively identified within the University of Pittsburgh Medical Center system from 2006-2020. We analyzed the association between appropriate ICD shocks within 1 year pre-LVAD with a primary composite outcome of death, stroke, and pump thrombosis and secondary outcomes of post-LVAD ICD shocks and ICD shock hospitalizations. Results: Among 309 individuals, average age was 57 ± 12 years, 87% were male, 80% had ischemic cardiomyopathy, and 42% were bridge to transplantation. Seventy-one patients (23%) experienced pre-LVAD shocks, and 69 (22%) experienced post-LVAD shocks. The overall prevalence of shocks pre-LVAD and post-LVAD were not different. Pre-LVAD ICD shocks were not associated with the composite outcome. Pre-LVAD ICD shocks were found to predict post-LVAD shocks (hazard ratio [HR] 5.7; 95% confidence interval [CI] 3.42-9.48; P <.0001) and hospitalizations related to ICD shocks from ventricular arrhythmia (HR 10.34; 95% CI 4.1-25.7; P <.0001). Conclusion: Pre-LVAD ICD shocks predicted post-LVAD ICD shocks and hospitalizations but were not associated with the composite outcome of death, pump thrombosis, or stroke at 1 year. The prevalence of appropriate ICD shocks was similar before and after LVAD implantation in the entire cohort.

Bicuspid evolution of the arterial and venous atrioventricular valves.

Atrioventricular valves were studied in pisces (shark), amphibians (frog), reptiles (turtle, snake and crocodile) and aves (duck, chicken and quail). Dog shark, Tiger shark and Hammerhead shark have a contractile common atrioventricular orifice with anterior and posterior bridging leaflets. Angel shark resembles the frog in having a contractile oval common atrioventricular orifice guarded by two lateral (right and left) and two central bridging (anterior and posterior) leaflets. In turtles and snakes the interatrial septation is complete. The common oval atrioventricular orifice is divided into two D-shaped orifices by the lower edge of the interatrial septum. Each orifice is guarded by a flap valve hanging down from the interatrial septum with rudimentary chordae tendinae, functionally corresponding to the septal leaflet of the human venous atrioventricular valve (VAVV) and the aortic leaflet of the human arterial atrioventricular valve (AAVV). There is no curved mural leaflet on either side related to curved contractile segments of the annuli. In crocodiles, the interventricular septation is complete. The VAVV is bicuspid with a prominent septal and diminutive mural component with no chordopapillary support. The AAVV is bicuspid with direct attachment of the fused commissural lines between the two leaflets to the ventricular musculature. In the aves, with four chambered hearts the VAVV has a curved mussular mural leaflet with a primitive muscular chorda and no septal leaflet. The AAVV resembles closely the human mitral valve. This study lends support to the view that VAVV and AAVV in man are similar in design and function with a D-shaped annulus and a skirt of leaflet tissue divisible into two functional units. The relatively straight part of the annuli suspend the straight leaflets; septal leafleft of the VAVV and aortic leaflet of the AAV. The curved annular components suspend the curved mural leaflets in both valves. Since this segment is contractile, the related mural leaflets of both valves need to have slits which split them into varying number of scallops to enable them to adapt themselves to the reduced systolic orifice and open widely during diastole. These scallops are best numbered as subsegments of the curved mural leaflet and not considered as separate leaflets. The curved leaflet of the VAVV needs to negotiate the acute border of the heart. Hence a major slit is usually present at this region which artificially divides it into an 'anterior' and 'posterior' portion resulting in assumption of a 'tricuspid' configuration.(ABSTRACT TRUNCATED AT 400 WORDS)

Independent multicenter study of Riata and Riata ST implantable cardioverter-defibrillator leads.

BACKGROUND: Riata and Riata ST leads (St Jude Medical, Sylmar, CA) are prone to failure. There are no independent multicenter reports regarding Riata or Riata ST lead performance. OBJECTIVE: To conduct a retrospective multicenter study of Riata and Riata ST leads that were implanted and followed at 7 centers. METHODS: The study included adults who received St Jude Medical Riata or Riata ST leads. Data for Quattro Secure leads were obtained from an earlier study. RESULTS: From 2002 to 2010, 1081 patients received a Riata (n = 774) or Riata ST (n = 307) lead. Follow-up was longer for Riata than Riata ST leads (4.2 ± 2.4 years vs 3.3 ± 1.7 years; P<.0001). During the study, 67 leads failed (6.2%), including 62 of 774 Riata (8.0%) and 5 of 307 Riata ST (1.6%) leads. Forty-seven of 67 lead failures (70.1%) were caused by electrical malfunction, and 20 lead failures (29.9%) were due to externalized conductors (ECs) that were electrically intact. Of 110 leads examined fluoroscopically, ECs were found in 26 of 81 Riata (32%) and 1 of 29 Riata ST (3.4%) leads. Of 26 Riata leads with ECs, 7 (27%) were malfunctioning. Riata leads had lower overall and malfunction free survival compared to Quattro leads (P<.0001), while Riata ST lead survival was not different (P = .422). CONCLUSIONS: The survival of Riata (but not Riata ST) leads was lower than Quattro leads; however, Riata ST leads had significantly shorter follow-up than Riata leads. ECs were common in Riata leads, and more than a quarter of Riata leads that had ECs were malfunctioning. Our observations suggest that systematic fluoroscopic examination of patients with Riata leads is appropriate.

Spatial changes in water quality of urban lakes in Chennai (India)--a case study.

Manifold increase in population of Chennai city (India) has resulted in a rapid decrease in the groundwater level due to its over exploitation. The Government of Tamil Nadu has been exploring various ways and means to combat this problem. The present study was undertaken to assess the quality of water in three important major lakes of Chennai and its suburbs such as Porur lake, Puzhal lake and Chembarambakkam lake which recharge the groundwater as well as these lakes are harnessed by the Tamil Nadu Government to supply potable water to the residents of Chennai. The parameters studied were colour, odour, taste, turbidity, temperature, pH, Dissolved Oxygen, Biological Oxygen Demand, Chemical Oxygen Demand, alkalinity, acidity, chlorides, Total Suspended Solids, Total Dissolved Solids and total hardness. Results indicate that the quality of water from these lakes is within the acceptable values. However, the TDS values were on the higher side in all the three lakes even though within the permissible limit prescribed by BIS. All the three lakes appear to be vulnerable to pollution as they are situated within or in close proximity to heavily populated areas.