Six-channel ECG-based pulse wave velocity for assessing whole-body arterial stiffness.

BACKGROUND: Despite the proposal of different means of non-invasive arterial stiffness assessment, none offers simultaneous information on whole-body peripheral arterial condition. We investigated the validity of applying a six-channel electrocardiogram-based pulse wave velocity (ECG-PWV) measurement system for this purpose. METHODS: The study consisted of two parts. Part One enrolled hypertensive (Group 1, n = 32) and normal (Group 2, n = 32) subjects, whereas Part Two recruited diabetic (Group 3, n = 50) and normal (Group 4, n = 50) subjects. To validate the application of ECG-PWV in assessing peripheral arterial stiffness in different parts of body, ECG-PWV data were compared with three other parameters including the cardio-ankle vascular index (CAVI), pulse wave velocity-digital volume pulse (PWV-DVP) and intima-media thickness (IMT). RESULTS: ECG-PWV in healthy subjects in Part One correlated significantly with CAVI and PWV-DVP (p < 0.05), whereas ECG-PWV and CAVI were significantly different between the hypertensive and normal subjects. Moreover, comparison of IMT and ECG-PWV from different sites showed significant correlation only between IMT and ECG-PWV from earlobe (r = 0.495, p = 0.004). No significant association, however, was noted between IMT and CAVI. For Part Two, significant differences existed between diabetic and normal subjects in body weight, waist circumference, level of HbA1c, fasting blood sugar, serum creatinine and ECG-PWV from the foot. However, no significant difference was noted in PWV-DVP between two groups. CONCLUSIONS: Six-channel ECG-PWV measurement system showed remarkable correlation with IMT in hypertensive subjects and with key anthropometric and biochemical parameters in diabetic patients, suggesting its validity in assessing whole-body arterial stiffness in subjects with peripheral arterial diseases within 10 min.

[Analysis of lipid-soluble components of Amomum villosum fruits by GC/MS].

OBJECTIVE: To analyse the lipid-soluble components of Amomum villosum fruits by GC/MS. METHODS: Lipid-soluble components in pericarps and seeds of A. villosum were extracted by Soxhlet extraction. The Lipid-soluble components were esterified and then analyzed by gas chromatography-mass spectrometry (GC-MS). RESULTS: Twenty-five and thirteen compounds were identified in pericarps and seeds of A. villosum, respectively, mainly including fatty acids and their esters. CONCLUSION: The results indicate that it is highly potential and significant to exploit its value in foods, medicines and healthy care.

Mechanical characterization of rabbit pulmonary vein sleeves in in vitro intact ring preparation.

BACKGROUND: Pulmonary vein (PV) sleeves, composed of cardiomyocytes, play certain roles in arrhythmogenesis. In the literature, it has been frequently reported that PV sleeves possess intrinsic spontaneous pacemaking activity and triggered activity in normal dogs and rabbits. In contrast, other research groups presented totally opposite findings which showed absence of such pacemakers in dogs, rabbits and rats. The present study was designed to clarify this puzzle and contradiction. METHODS: A novel methodology using in vitro experimentation was used to examine the electromechanical activity of whole segments of PV sleeves. The ring preparation was composed of a small piece of left atrial (LA) free wall, PV ostium and sleeve from rabbits. A circumferential contraction of the PV sleeve was measured when the preparation was electrically driven from the LA free wall. Mechanical force of the ring preparation was measured using a force transducer. The action potentials were recorded using conventional intracellular recording technique in strip preparation. RESULTS: In 15 rabbits, no spontaneous pacemaking activity or triggered activity was found in the in vitro ring preparation of PV sleeve. The circumferential contraction of PV sleeves was external calcium-dependent. Frequency-force relation displayed a negative staircase at 0.1-0.5 Hz and a positive staircase at 1-5 Hz. Post-rest potentiation was prominent between 15 s and 120 s. Intracellular action potential recording did not display any automaticity or triggered activity in PV sleeves. CONCLUSION: In an intact ring preparation of rabbit PV sleeves, intrinsic spontaneous pacemaking activity or triggered activity was not found.

Measuring pulse wave velocity using ECG and photoplethysmography.

Pulse wave velocity (PWV) is a useful method to assess arterial stiffness and predict mortality of atherosclerosis-related diseases. The progression of atherosclerosis is not homogeneous. There must be difference of PWV between sites by site. Therefore we designed a multi-channel instrument to measure PWV at different sites of the body simultaneously. We measured PWV at six different regions simultaneously. Thirty four healthy adults received the measurement. We found that PWVs were higher in the large vessels, by measuring from the heart to toes and heart to fingers as compared with the measurement from the heart to the earlobes (4.76 ± 0.46 m/s; 4.67 ± 0.41 m/s; 1.10 ± 0.16 m/s). The PWV of the left and right sides were the same. Although there were statistically significances, the correlation of PWV between foot and hand is better than those between ear and foot and between ear and hand. Herein we presented a novel and reliable measurement of PWV. The changes of PWV in different regions may be used in predicting disease processes such as stroke, coronary artery diseases and renal diseases, respectively.