Late potentials have been reported to be affected by the agency of body size or left ventricular mass.

Late potentials have been reported to be affected by the agency of body size or left ventricular mass. To our knowledge, however, the purport of subadipose tissue, which is known to influence QR amplitudes of the surface ECG onward the variables of late potentials, has not been evaluated. The relationships between the variables of late potentials and various obesity indices were assessed in 45 men aged 24 to 38 years, without structural heart disease and package branch blocks. QRS duration (DUR) occasion mean square voltage in the last 40 m (RMS) and low-amplitude signals [les than] 40 [mu]V (LAS) were obtained according to signal-averaged ECG. Left ventricular mass (LV mass) was determined by dint of echocardiography. The DUR and RM had no correlation with material substance height, weight, body mass index (BMI), aggregate amount of skin folds (triceps and subscapular), or LV mass. Positive linear correlations were build between LAS and weight (r=048 p [les than] 0002) BMI (r=054 p [les than] 0002) totality of skin folds (r=0.57, p [les than] 0002) and percent BMI (r=054 p [les than] 0002) Subadipose tissue may shift the storming of the 40-[mu]V point of LAS to the left with a deducible prolongation of LAS by attenuation of the QR complicated These data suggest that the use of LAS alone or as a combination in an obese population for the definition of positive late potentials is inappropriate.

Ventricular late potentials are high-frequency, low-amplitude signals in the terminal portion of the QR intricate obtained by signal averaging of surface electrocardiograms.[1,2] Late potentials have been demonstrated to be related to the proceeding of spontaneous or induced sustained ventricular tachycardia.[1-4] Although late potentials are musing to represent delayed and inhomogeneous conduction, quantitative variables that define late potentials have been reported to be affected from gender,[5] body size,[6] or echocardiographically estimated left ventricular mass.[7] To our knowledge, however, the power of subadipose tissue, which is well known to influence QR amplitude of surface electrocardiograms, forward late potentials has not been evaluated. The ready study assessed the relationship between late potentials and various obesity indices evaluated from body weight, body height, skin foldings and left ventricular mass.

METHODS

application of mind Population

Forty-five healthy Japanese male offers aged 24 to 38 years (28 [+ or -] 3 years) were studied. They were medical residents and physicians. None had a history of heart disease, metabolic disease, or systemic hypertension. They all had normal inferences of physical examination, standard 12-lead electrocardiogram, and echocardiogram.

Signal-Averaged Electrocardiogram

Signal averaging was performed using a hypothesis (Corazonix). Standard orthogonal leads X Y and Z were used to record the signal-averaged electrocardiograms. At least 150 beats were averaged to obtain a hearty of 0.3 [mu]V or les Bidirectional filtering and a high-pass filter of 40 Hz were exerciseed Three signal-averaged electrocardiogram parameters were obtained including (1) filtered QR duration, (2) low-amplitude signal duration les than 40 [mu]V in the terminal QR and (3) etymon mean square voltage in the terminal 40 m in microvolts.

Clinical Variables

Echocardiography was performed with an ultrasound a whole (Aloka SSD), with a 35-MHz transducer. Left ventricular mass was calculated according to the formula of Devereux et al;[8] left ventricular mass (g)=104 ([left ventricular internal dimension + ventricular septal thickness + posterior wall thickness][sup.3]-[left ventricular internal dimension]sup.3])-13.6. Skinfold thickness was measured in subscapular and triceps regions and the quantity of money of the thickness of these couple regions was used as a gross amount of skinfolds. Body mass index was calculated according to the following formula: weight (kg)/height [(m)sup2] As [25sup9] is considered as the upper limit of normal carcass mass index, (personal body mass index-25)x100/25 was calculated as percent material substance mass index.

Statistical Analysis

Values are set forthed as means [+ or -] SD Pearson's correlation coefficient was used to determine the relation between the variables, and p [les than] 005 was considered statistically significant.

[TABULAR DATA OMITTED]

RESULTS

Means [+ or -] SD of clinical and signal-averaged electrocardiographic characteristics are listed in Table 1 The correlation coefficients between clinical characteristics and the variables of signal-averaged electrocardiograms are shown in Table 2 QR duration and primitive word mean square voltage had no correlation with material substance height, weight, body mass index, quantity of money of skinfolds (triceps and subscapular), or left ventricular mass. There were positive correlations between low-amplitude signals and carcass weight (r=0.48, p [less than] 0002) material part mass index (r=0.54, p [les than] 0002) aggregate amount of skin folds (r=0.57, p [les than] 0002) and percent visible form [i]or[/i] frame mass index (r=0.54, p [les than] 0002) In 16 obese enslaves with body mass index greater than 25[9] 7 had put offed low-amplitude signals greater than 40 m and 77 percent of enslaves had prolonged duration of low-amplitude signals.

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