Effectiveness of Ventricular Intrinsic Preference (VIP™) and Ventricular AutoCapture (VAC) algorithms in pacemaker patients: Results of the validate study.

BACKGROUND: Several past clinical studies have demonstrated that frequent and unnecessary right ventricular pacing in patients with sick sinus syndrome and compromised atrio-ventricular conduction (AVC) produces long-term adverse effects. The safety and efficacy of two pacemaker algorithms, Ventricular Intrinsic Preference™ (VIP) and Ventricular AutoCapture (VAC), were evaluated in a multi-center study in pacemaker patients. METHODS: We evaluated 80 patients across 10 centers in India. Patients were enrolled within 15 days of dual chamber pacemaker (DDDR) implantation, and within 45 days thereafter were classified to either a compromised AVC (cAVC) arm or an intact AVC (iAVC) arm based on intrinsic paced/sensed (AV/PV) delays. In each arm, patients were then randomized (1:1) into the following groups: VIP OFF and VAC OFF (Control group; CG), or VIP ON and VAC ON (Treatment Group; TG). Subsequently, the AV/PV delays in the CG groups were mandatorily programmed at 180/150 ms, and to up to 350 ms in the TG groups. The percentage of right ventricular pacing (%RVp) evaluated at 12-month post-implantation follow-ups were compared between the two groups in each arm. Additionally, in-clinic time required for collecting device data was compared between patients programmed with the automated AutoCapture algorithm activated (VAC ON) vs. the manually programmed method (VAC OFF). RESULTS: Patients randomized to the TG with the VIP algorithm activated exhibited a significantly lower %RVp at 12 months than those in the CG in both the cAVC arm (39±41% vs. 97±3%; p=0.0004) and the iAVC arm (15±25% vs. 68±39%; p=0.0067). In-clinic time required to collect device data was less in patients with the VAC algorithm activated. No device-related adverse events were reported during the year-long study period. CONCLUSIONS: In our study cohort, the use of the VIP algorithm significantly reduced the %RVp, while the VAC algorithm reduced in-clinic time needed to collect device data.

Clinical and echocardiographic diagnosis, follow up and management of right-sided cardiac thrombi.

BACKGROUND: Right-sided cardiac masses are infrequent and have varied clinical presentation. The present study describes the clinical features, echocardiographic findings and management of 19 patients presenting with right-sided cardiac thrombi in a tertiary care center in north India. METHODS: This is a retrospective, single center observational study of consecutive patients over the period January 2003-2008 admitted in our emergency intensive care unit (EICU). We identified 38 patients with right-sided cardiac masses admitted to EICU diagnosed by transthoracic echocardiography of which 19 patients had right-sided thrombus. The echocardiographic findings were reviewed by two cardiologists in all patients. Treatment was not standardized and choice of therapy was based on judgment of attending physician. RESULTS: The mean age of patients with cardiac thrombus was 36.6 ± 11.8 years. Right atrial (n = 17) and right ventricle (n = 2) thrombi were associated with deep vein thrombosis (DVT) in 7 (36.8%) and pulmonary embolism in 3 (15%) patients. 13 (68.4%) patients appeared to have in situ mural thrombus. 12 patients were managed with oral anticoagulants, 3 patients underwent surgery and 4 patients were thrombolysed. All the survivors had a mean follow-up of 40 ± 6 months (range--18-50 months). CONCLUSIONS: Prompt echocardiographic examination in an appropriate clinical setting facilitates faster diagnosis and management of patients with right-sided cardiac thrombi. High incidence of in situ mural thrombus and varied comorbidities predisposing to right-sided cardiac thrombi besides DVT and pulmonary embolism need to be recognized. Oral anticoagulation and thrombolysis appear to be the mainstay of treatment with surgery limited for selected patients.

Cardiac amyloidosis--two case reports with variable presentation.

Many cases of progressive heart failure due to cardiac amyloidosis remain undiagnosed due to the rarity and lack of suspicion on part of physician. Treatment options are limited and patients are also poor responders in later stages. Hence, early diagnosis by recognition of syndromic presentation and diagnostic modalities is helpful in retarding the disease process.

Rodents as reservoirs of parasites in India.

We monitored the prevalence of endoparasitic infections of rodents in Punjab State, India, between January 2004 and December 2005. Three species of wild rodents, namely the house rat, Rattus rattus (n= 42), the lesser bandicoot rat, Bandicota bengalensis (n= 34) and the Indian gerbil, Tatera indica (n= 15), were live-captured from houses and crop fields. Examination of various organs revealed that the highest rates of endoparasitic infection occurred in R. rattus (40.5%), followed by B. bengalensis (35.3 %) and then T. indica (20.0%), with an overall infection rate of 35.2%. All three rodent species were found naturally infected with one or more species of helminths. Metacestodes (1-6) of Cysticercus fasciolaris (larvae of Taenia taeniaeformis) were found in all three rodent species (in the liver). In one male T. indica, numerous robust T. taeniaeformis metacestodes were found in oval sacs attached to the mesentery and the abdominal wall, an unusual site. The cauda epididymal fluid of the same gerbil was also found to be infected with a very rare species of strongylid nematode, which could not be identified to genus or species level. It is possible that this nematode is transmitted sexually and thus may affect the reproductive potential of gerbils. This appears to be the first report of this phenomenon. In one B. bengalensis individual, the intestine was found to be obstructed with an acanthocephalan, Moniliformis moniliformis, with concurrent infection with C. fasciolaris in the form of multiple cysts in the liver. Although no natural protozoan infection was found in these field rodents, experimental Trypanosoma evansi infection has been established in all three species with high pathogenicity, and the possibility of sexual transmission was supported by the presence of T. evansi in the cauda epididymal fluid of male rats.

Prevalence of sustained hypertension and obesity in urban and rural school going children in Ludhiana.

BACKGROUND: Increasing trend of hypertension is a worldwide phenomenon. The data on sustained hypertension in school going children is scanty in India. The present study was conducted to evaluate the prevalence of sustained hypertension and obesity in apparently healthy school children in rural and urban areas of Ludhiana using standard criteria. METHODS AND RESULTS: A total of 2467 apparently healthy adolescent school children aged between 11-17 years from urban area and 859 students from rural area were taken as subjects. Out of total 3326 students, 189 were found to have sustained hypertension; in urban areas prevalence of sustained hypertension was 6.69% (n=165) and in rural area it was 2.56% (n=24). Males outnumbered females in both rural and urban areas. The mean systolic and diastolic blood pressure of hypertensive population in both urban and rural population was significantly higher than systolic and diastolic blood pressure in their normotensive counterparts (urban normotensive systolic blood pressure:115.48+/-22.74 mmHg, urban hypertensive systolic blood pressure: 137.59+/-11.91 mmHg, rural normotensive systolic blood pressure: 106.31+/-19.86 mmHg, rural hypertensive systolic blood pressure: 131.63+/-10.13 mmHg, urban normotensive diastolic blood pressure: 74.18+/-17.41 mmHg, urban hypertensive diastolic blood pressure: 84.58+/-8.14 mmHg, rural normotensive diastolic blood pressure: 68.84+/-16.96 mmHg, rural hypertensive diastolic blood pressure: 79.15+/-7.41 mmHg). Overweight populationwas significantly higher in urban area. There were 287 (11.63%) overweight students and 58 (2.35%) were obese. In rural population overweight and obese students were 44 (4.7%) and 34 (3.63%) respectively. There was significant increase in prevalence of hypertension in both rural and urban population with increased body mass index in urban students; those with normal body mass index had prevalence of hypertension of 4.52% (n=96), in overweight it was 15.33% (n=44) and in obese it was 43.10% (n=25). In rural area, the overweight students showed prevalence of sustained hypertension in 6.82% (n=3) and in obese group it was 61.76% (n=21). None of the student with normal body mass index in rural area was found to be hypertensive. The mean body mass index of hypertensive population in both rural and urban areas was significantly higher than respective normotensive population (mean body mass index in urban normotensive group: 20.34+/-3.72 kg/m2, hypertensive group: 24.91+/-4.92 kg/m2; mean body mass index in rural normotensive group: 18.41+/-3.41 kg/m2, hypertensive group: 21.37+/-3.71 kg/m2, p<0.01). CONCLUSIONS: Prevalence of sustained hypertension is on the rise in urban area even in younger age groups. Blood pressure is frequently elevated in obese children as compared to lean subjects. This is possibly related to their sedentary lifestyle, altered eating habits, increased fat content of diet and decreased physical activities.