Effect of rate-adaptive pacing on performance and physiological parameters during activities of daily living in the elderly: results from the CLEAR (Cylos Responds with Physiologic Rate Changes during Daily Activities) study.

AIMS: For most elderly pacemaker patients, evaluation of rate-adaptive pacing using treadmill and bicycle tests is impractical and not representative of typical daily activities. This study was designed to compare the performance and physiological response of the closed-loop stimulation (CLS) rate-adaptive sensor to accelerometer (XL) and no rate sensor (DDD) during typical daily activity testing. METHODS AND RESULTS: Subjects recently implanted with a Cylos pacemaker completed timed activities of daily life testing, which included walking, sweeping, and standing from a seated position. Activity performance and physiological response from each sensor mode was evaluated for subjects requiring ≥80% pacing. Overall, 74 subjects needed ≥80% pacing during at least one test. An increase in the area swept (CLS vs. XL, 1.67 m(2) difference, P = 0.009; CLS vs. DDD, 1.59 m(2) difference, P = 0.025) and a decrease in the prevalence of orthostatic hypotension (OH) after standing 1 min (CLS vs. XL, odds ratio = 0.16, P = 0.006; CLS vs. DDD, odds ratio = 0.18, P = 0.012) was observed in the CLS mode as compared with XL and DDD. No statistical difference in walk distance was observed between CLS and XL or CLS and DDD. CONCLUSION: In acute testing, as compared with XL and DDD, CLS provides a more physiological response during the performance of activities of daily living for subjects with ≥80% pacing. This is clinically reflected in better performance during the sweep test as well as a decrease in the prevalence of OH in our elderly population. Clinicaltrials.gov identifier: NCT00355797.

The progression of cardiovascular risk to cardiovascular disease.

A cluster of risk factors associated with obesity defines the metabolic syndrome and identifies cardiometabolic risk. Accumulation of fat in the visceral depot is a more reliable predictor of cardiovascular disease than is total body mass or body mass index. The recent discovery of the endocannabinoid-CB1 receptor system and its impact on the regulation of energy metabolism represents a significant advance that will help target visceral fat and its metabolic implications. As a highly active endocrine organ, visceral fat secretes many bioactive molecules, known as adipokines. Dysregulation of these adipokines contributes to the pathogenesis of the obesity-associated metabolic syndrome, resulting in insulin resistance, type 2 diabetes, hypertension, hyperlipidemia, and vascular disease. Even modest weight reduction leads to reduced cardiometabolic risk by affecting the individual components comprising the metabolic syndrome.

Transesophageal Echocardiographic Assessment of Lesions of the Right Ventricular Outflow Tract and Pulmonic Valve.

To establish the role of biplane transesophageal echocardiography (TEE) in the assessment of congenital and acquired lesions involving the right ventricular outflow tract (RVOT) and pulmonic valve (PV), 28 consecutive RVOT and PV lesions in 22 consecutive patients were studied by two-dimensional and color Doppler transthoracic echocardiograms (n = 22), horizontal (n = 22) and vertical (n = 22) plane TEEs, cardiac catheterization (n = 15), cardiac surgery (n = 6), and magnetic resonance imaging (n = 1). Sixteen patients had congenital lesions, and six had acquired lesions. Longitudinal TEE clearly imaged 25 of 28 abnormalities, transverse TEE clearly imaged 12 of 28, and transthoracic echocardiography clearly imaged 9 of 28. Two-dimensional TEE scanning revealed the lesion or site of stenosis. Color Doppler revealed conspicuous mosaic jets in relation to a structural abnormality in most cases. Longitudinal TEE was more sensitive in the detection of small vegetations of the PV, in the depiction of PV doming in cases of valvar pulmonic stenosis, and in the display of the RVOT and PV so that the longitudinal extent of involvement of larger masses could be appreciated. However, longitudinal TEE was not able to assess the gradient of a stenosis at the RVOT or PV level in any case. Biplane TEE is helpful in the anatomic assessment of congenital and acquired lesions of the RVOT and PV in adults. (ECHOCARDIOGRAPHY, Volume 13, January 1996)