Impact of milrinone on mitral annular velocity in patients with congestive heart failure.

PURPOSE: The purpose of this study is to assess the impact of milrinone on mitral annular velocity in patients with congestive heart failure. METHOD: We studied 27 patients with congestive heart failure. All patients underwent transthoracic echocardiography both before and after administration of milrinone. We measured the early transmitral velocity (E) and the mitral annular early diastolic velocity (Ea). The ratio of E to Ea (E/Ea) was calculated. After the baseline echocardiography, milrinone was administered as a continuous infusion at a rate of 0.25 µg/kg/min. Echocardiographic measurements were repeated 4 h after milrinone was begun. RESULTS: After administration of milrinone, Ea was significantly increased, while E/Ea was significantly decreased. The population of 27 patients was divided into 20 (74 %) with left ventricular ejection fraction (LVEF) <50 % and seven (26 %) with LVEF ≥50 %. Ea was significantly increased in both groups, while E/Ea was significantly decreased. CONCLUSION: Even low-dose milrinone produced an improvement in left ventricular (LV) diastolic function, as evidenced by an increase in Ea, and falls in LV filling pressures, as determined by a decrease in E/Ea, in patients with congestive heart failure throughout a wide range of LV systolic function.

Characteristics of induced ventricular fibrillation cycle length in symptomatic Brugada syndrome patients.

BACKGROUND: Limited information is available on the ventricular fibrillation (VF) spectrum in Brugada syndrome (BS) patients. We clarified differences in the VF cycle length (CL) using fast-Fourier transformation (FFT) analysis in symptomatic and asymptomatic BS patients. METHODS AND RESULTS: VF was induced by pacing from the right ventricular (RV) apex and/or RV outflow tract (RVOT) for >8s. A 4096-point FFT analysis of results from 28 male BS patients (51.1 ± 13.7 years old) was performed. Dominant frequency (DF) from phases 1 (4s) to 6 was obtained at 2-s intervals. The average DF from surface and intracardiac electrograms (ECG: DF(ECG); ICE: DF(ICE,), respectively) was compared between symptomatic and asymptomatic patients. Symptomatic patients had a significantly shorter effective refractory period at a CL of 600 ms at the RVOT than asymptomatic patients. DF(ECG) significantly increased with phase (5.64 ± 0.32 Hz in phase 1 to 6.16 ± 0.52 Hz in phase 6) and was significantly higher in symptomatic patients than in asymptomatic patients. DF(ICE) had the same characteristics as DF(ECG). CONCLUSIONS: Induced VF in BS patients can be characterized using FFT analysis. Our data support the hypothesis that symptomatic patients have a significantly shorter VF CL than asymptomatic patients.

Cardio-ankle vascular index is superior to brachial-ankle pulse wave velocity as an index of arterial stiffness.

Both cardio-ankle vascular index (CAVI) and brachial-ankle pulse wave velocity (baPWV) are noninvasive methods to estimate arterial stiffness. The purpose of this study is to determine whether CAVI or baPWV is superior as an index of arterial stiffness. One hundred and thirty patients with chest pain syndrome who underwent coronary angiography (CAG) were included in this study. We obtained intima-media-thickness (IMT) and the stiffness parameter beta of the carotid artery by carotid ultrasounds (CU). The peak early diastolic velocity (E), deceleration time of E (EDCT), peak atrial systolic velocity (A) of transmitral flow and left ventricular mass index (LVMI) were obtained by echocardiography. CAVI, baPWV, total cholesterol (T-C), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triglycerides (TG) were measured before CAG. There was a significant correlation between CAVI and baPWV (r = 0.64, p < 0.01). Both CAVI and baPWV were significantly correlated with age, IMT and beta (age: r = 0.64, p < 0.01 for CAVI, and r = 0.48, p < 0.01 for baPWV; IMT: r = 0.40, p < 0.01, and r = 0.31, p < 0.01; beta: r = 0.36, p < 0.01 and r = 0.25, p < 0.01). However, only CAVI was correlated with the parameters of left ventricular diastolic indices from echocardiography (E/A: r = 0.44, p < 0.01; EDCT: r = 0.36, p < 0.01). Additionally, LDL-C and T-C/HDL-C were also associated with only CAVI (LDL-C: r = 0.26, p < 0.02; T-C/HDL-C: r = 0.30, p < 0.01), not baPWV. Finally, only CAVI was significantly higher in the group with angina pectoris than in the normal group (9.708 +/- 1.423 vs. 9.102 +/- 1.412; p = 0.0178). All parameters associated with atherosclerosis suggested that CAVI was superior to baPWV as a parameter of arterial stiffness.

Distal radial arterial hypertrophy after transradial intervention: A serial intravascular ultrasound study.

BACKGROUND: Transradial intervention (TRI) may cause damage to the radial artery (RA). We have demonstrated intima-media thickening and luminal narrowing of the distal RA after TRI using intravascular ultrasound (IVUS). This study aimed to determine the predictors of intima-media thickening of RA after TRI in the same patients using serial IVUS. METHODS AND RESULTS: We enrolled 110 consecutive patients who underwent TRI. IVUS of RA was immediately performed after TRI and repeated 6 months later. Volumetric analyses were performed for the distal RA. The intima-media volume (IMV) increased from 53.56±10.85mm3 to 58.70±13.04mm3 (p=0.0022), whereas the lumen volume (LV) decreased from 146.87±40.53mm3 to 129.64±45.78mm3 (p=0.0018) and vessel volume (VV) decreased from 201.23±44.55mm3 to 188.34±52.25mm3 (p=0.0306). Multiple regression analysis revealed diabetes as the most powerful independent predictor of the percentage change in IMV of the distal RA after TRI. The percentage change in IMV significantly increased in the DM group compared with non-DM group (p<0.001). The percentage change in IMV was significantly positively correlated with HbA1c. CONCLUSIONS: Serial IVUS of the distal RA revealed a significant increase in IMV and decreases in LV and VV. Diabetes was the most powerful independent predictor of the percentage change in IMV of the distal RA after TRI. The percentage change in IMV was significantly positively correlated with HbA1c.

Effects of isoproterenol and propranolol on the inducibility and frequency of ventricular fibrillation in patients with Brugada syndrome.

BACKGROUND: Isoproterenol (ISP), a beta-adrenergic agonist, suppresses arrhythmic storm in patients with sporadic Brugada syndrome (BS). However, the influence of ISP and the beta-adrenergic antagonist propranolol (PRO) on the inducibility and frequency of ventricular fibrillation (VF) in BS patients remains unclear. METHODS AND RESULTS: Twenty-seven BS patients with induced VF>10s in a control state were enrolled. Electrophysiological stimulation (EPS) testing was performed during ISP and after PRO in selected patients. The inducibility and frequency of VF were compared. Dominant frequency (DF) was obtained by Fast Fourier transform from 4-s data (phase) and sequentially every 2s up to phase 5. ISP prevented induction of VF in 20 of 25 patients (80%). During ISP, 5 patients experienced induction of VF. ISP significantly influenced DF transition compared with the control state. DF gradually increased but was unchanged after the middle phase. PRO had no effect on incidence of induced VF in 5 patients; increased PRO induced VF in 5 (83.3%) of 6 patients who tested negative during ISP. After PRO, 10 patients experienced induction of VF. Thus, PRO significantly influenced DF transition. DF after PRO was higher than that in the corresponding phase in the control state. CONCLUSION: ISP suppressed induction of VF and the increase of DF with time. PRO aggravated VF and accelerated DF.

Effects of mineralocorticoid receptor antagonist spironolactone on atrial conduction and remodeling in patients with heart failure.

BACKGROUND: Spironolactone was shown to reduce mortality in patients with heart failure (HF). However, the effect of spironolactone on the incidence of atrial fibrillation remains unknown. Therefore, we examined the effects of spironolactone on atrial conduction and remodeling in patients with HF. METHODS AND RESULTS: A total of 21 patients with HF were divided into either spironolactone group (n=11) or control group (n=10). The patients were followed up for 12 months. Blood examination, echocardiogram, and signal-averaged electrocardiogram were performed at study enrollment and after 3 and 12 months of treatment. In the spironolactone group, atrial natriuretic peptide tended to reduce, left atrium dimension was significantly smaller, the ratio of E wave to A wave tended to improve, and P-duration was significantly shortened. CONCLUSIONS: Spironolactone improves atrial conduction and remodeling in patients with HF.

Cardio-ankle vascular index is a new noninvasive parameter of arterial stiffness.

BACKGROUND: Beta is an index of arterial stiffness independent of blood pressure. Beta of the thoracic descending aorta (TDA) has been obtained by transesophageal echocardiography (TEE) and the cardio-ankle vascular index (CAVI) is a new noninvasive estimation of beta. METHODS AND RESULTS: The purpose of this study was to evaluate the accuracy and usefulness of CAVI and to compare it with other parameters of arteriosclerosis by carotid ultrasound (CU). The instantaneous dimensional change of the TDA on TEE was measured simultaneously with systemic pressure of the brachial artery in 70 patients in sinus rhythm. There were significant correlations between CAVI and age (r=0.65, p<0.01), and CAVI and the beta from TEE (Aobeta) (r=0.67, p<0.01). Next, 110 patients with chest pain syndrome underwent CU and measurement of CAVI, intima - media thickness (IMT), plaque score and beta. There were significant relationships between CAVI and IMT (r=0.42, p<0.01), and between CAVI and beta (r=0.39, p<0.01). CAVI of the group diagnosed with plaque was significant higher than that of the normal group (9.872+/-1.464 vs 9.038+/-1.377, p=0.0039). CONCLUSIONS: CAVI is measured easily and noninvasively and is a new index of arterial stiffness that is independent of blood pressure.