Hypertension

ORIGINAL ARTICLE

DOI 10.4070/kcj.2011.41.4.191

Print ISSN 1738-5520 / On-line ISSN 1738-5555 Copyright © 2011 The Korean Society of Cardiology

Open Access

Non-Dipper Pattern is a Determinant of the Inappropriateness of Left Ventricular Mass in Essential Hypertensive Patients
Bae Keun Kim, MD, Young-Hyo Lim, MD, Hyung Tak Lee, MD, Jae Ung Lee, MD, Kyung Soo Kim, MD, Soon Gil Kim, MD,Jeong Hyun Kim, MD, Heon Kil Lim, MD and Jinho Shin, MD
Division of Cardiology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea

ABSTRACT
Background and Objectives: Inappropriately high left ventricular mass (iLVM) is known to be related to cardiovascular

prognosis. A non-dipper pattern has a greater mean left ventricular (LV) mass than the dipperpattern in hypertensive patients. However, the appropriateness of LV mass in dipper or non-dipper patterns has not been adequately investigated. The aim of this study was to define the relationship between nocturnal dipping and the appropriateness of LV mass. Subjects and Methods: Using the ambulatory blood pressure monitoring (ABPM) database, the data of 361 patients who underwent ABPM andechocardiography was analyzed retrospectively. Appropriateness of LV mass was calculated as observed/predicted ratio of LV mass (OPR) using a Korean-specified equation. Nocturnal dipping was expressed as percent fall in systolic blood pressure (BP) during the night compared to the day. Results: Daytime, nighttime and 24 hours BP in hypertensive patients was 140.4±14.8 mmHg, 143.7±15.2 mmHg and 129.4±20.0mmHg, respectively. OPR was 106.3±19.9% and nocturnal dipping was 10.2±10.9 mmHg. In a multiple linear regression model, 24 hours systolic BP (β=0.097, p=0.043) and nocturnal dipping (β=-0.098, p=0.046) were independent determinants of OPR as well as age (β=0.130, p=0.025) and body mass index (BMI) (β=0.363, p1.5 mg/dL in male), any regional wall motion abnormalities, grade II or more valvularregurgitation, any valvular stenosis, M-mode interrogation angle >10 degrees and cardiomyopathy based on the echocardiographic findings. Height, weight, clinical BP and heart rate were measured during the study period before ABPM and echocardiography were performed. The study protocol was approved by the Institutional Review Board (IRB) of Hanyang University Medical Center at Seoul. An informed consentprocess from each patient regarding the process of the examination and use of the data was made exempt by the IRB. Blood pressure determination Clinic BP was measured using a mercury sphygmomanometer as the average of at least 3 measurements by a physician or qualified nurse. ABPM was recorded during a routine day by a TM-2430 device (A&D, Saitama, Japan). The device was applied to thenon-dominant arm and was applied for 24 hours. BP was measured every 15 minutes during the daytime and every 30 minutes at nighttime, which was between 10 PM and 6 AM. The patients were instructed to maintain their usual activities during the monitoring process and to stay calm

Echocardiography Two dimensional and guided M-mode echocardiograms were performed on each subject by a single sonographer with acommercially available machine (iE33; Philips medical system, Andover, MA, USA) using a 1-5 MHz transducer. Mmode tracings were recorded on strip-chart paper at 50 mm/s. Measurements of interventricular septal thickness, posterior wall thickness, and LV dimensions were performed at or just below the mitral valve tips, by the leading edge-to-leading edge method, according to the American Society ofEchocardiography recommendations.12) LV mass was calculated by the following equation, {1.04×(IVSd+LVDd+PWTd)3-LVDd3}× 0.8+0.6,13) where IVSd is diastolic interventricular septum, LVDd is diastolic left ventricular dimension, and PWTd is diastolic posterior wall thickness. We adopted the LV mass index by the height to highlight the effect of weight and set the cutoff value {mean+ 2 standard...