Nobuhiko Haruki

Comparison of acute and chronic impact of adaptive servo-ventilation on left chamber geometry and function in patients with chronic heart failure.

The aim of this study was to determine differences in the acute and chronic impact of adaptive servo‐ventilation (ASV) on left chamber geometry and function in patients with chronic heart failure (CHF).

Age- and Gender-Dependency of Left Ventricular Geometry Assessed with Real-Time Three-Dimensional Transthoracic Echocardiography

BACKGROUND Aging and gender may affect left ventricular (LV) mechanics. The aim of this study was to determine the age and gender dependency of LV mechanical indices obtained from real-time three-dimensional echocardiography (RT3DE). METHODS RT3DE was performed in 280 healthy subjects (age range, 1-88 years; 137 men). From full-volume data sets, LV endocardial and epicardial borders were semiautomatically traced using quantitative software. LV volumes and corresponding long-axis diameter were measured throughout the cardiac cycle. Sphericity index was defined as the ratio of LV volume and spherical volume, calculated as 4/3 × π × (long-axis diameter/2)(3). LV mass was calculated as (LV epicardial volume - LV endocardial volume) × 1.05. The ratio of LV mass to LV volume was also calculated. RESULTS The mean value of LV ejection fraction did not change with age. However, LV volumes, mass, sphericity index, and LV mass/volume ratio were altered by age: (1) sphericity index was highest in the first decade of age and then declined until the fifth decade, (2) LV mass/volume ratio significantly increased in older age, and (3) LV mass/volume ratio was significantly higher in aged women compared with age-matched men. CONCLUSIONS Age has heterogeneous effects on LV shape and LV mass/volume ratio, potentially due to the growing process of myocardial fibers and the surrounding architecture in the younger population, as well as the aging process, with an increase in vascular stiffness and a loss of myocytes in older populations. Higher LV mass/volume ratios in older women might be a contributor to the preferential development of diastolic heart failure in this population.

Prognostic value of LA volumes assessed by transthoracic 3D echocardiography: comparison with 2D echocardiography.

OBJECTIVES The hypothesis of this study was that minimal left atrial volume index (LAVImin) by 3-dimensional echocardiography (3DE) is the best predictor of future cardiovascular events. BACKGROUND Although maximal left atrial volume index (LAVImax) by 2-dimensional echocardiography (2DE) is a robust index for predicting prognosis, the prognostic value of LAVImin and the superiority of measurements by 3DE over 2DE have not been determined in a large group of patients. METHODS In protocol 1, we assessed age and sex dependency of LAVIs using 2DE and 3DE in 124 normal subjects and determined their cutoff values (mean + 2 SD). In protocol 2, 2-dimensional (2D) and 3-dimensional (3D) LAVImax/LAVImin were measured in 556 patients with high prevalence of cardiovascular disease. After excluding patients with atrial fibrillation, mitral valve disease, and age <18 years, 439 subjects were followed to record major adverse cardiovascular events (MACE). Patients were divided into 2 groups by the cutoff criteria of LAVI in each method. RESULTS In protocol 1, there was no significant age and sex dependency for each 2D and 3D LAVI. In protocol 2, during a mean of 2.5 years of follow-up, MACE developed in 88 patients, including 32 cardiac deaths. Kaplan-Meier survival analyses showed that all 4 LAVI cutoff criteria had significant predictive power of MACE. After variables were adjusted for clinical variables and left ventricular ejection fraction, all 4 methods were still independently and significantly associated with MACE, but 3D-derived LAVImin had the highest risk ratio. 3D LAVImin also had an incremental prognostic value over 3D LAVImax. CONCLUSIONS LAVIs by both 2DE and 3DE are powerful predictors of future cardiac events. 3D LAVImin tended to have a stronger and additive prognostic value than 3D LAVImax.

Pitfalls of anatomical aortic valve area measurements using two-dimensional transoesophageal echocardiography and the potential of three-dimensional transoesophageal echocardiography.

AIMS The aims of this study were to (i) investigate aortic annulus dynamics using two-dimensional (2D) speckle tracking echocardiography, (ii) determine optimal 2D short-axis view for the calculation of planimetric aortic valve area (AVA), and (iii) compare 2D planimetric AVA extracted from volumetric three-dimensional data sets using real-time 3DTEE (three-dimensional transoesophageal echocardiography) with standard 2DTEE planimetry. METHODS AND RESULTS We studied 60 patients with aortic stenosis (AS) and 10 control subjects. AVA was calculated by standard 2DTEE planimetry method, volumetric 3DTEE method, and continuity equation (CE) from transthoracic echocardiography. In addition, aortic annular motion was studied using 2D speckle tracking. Aortic annulus moves cranially during early systole and subsequently moves caudally during the remainder of systole and isovolumic relaxation. Annulus again moved in the cranial direction during diastole in both groups. Although AVA correlated well between 2DTEE and 3DTEE methods (r = 0.95), 2DTEE showed a significantly larger AVA compared with 3DTEE method (1.26 +/- 0.39 vs. 1.10 +/- 0.39 cm(2), P < 0.001). In patients in whom aortic cusps were visible in 2DTEE short-axis images during systole only (n = 45), AVA using 2DTEE was still larger than that measured with 3DTEE. However, the bias in AVA was significantly lower compared with the remaining 15 patients (-0.13 +/- 0.11 vs. -0.26 +/- 0.12 cm(2), P < 0.005). Although both methods showed moderate correlation with AVA by CE (r = 0.78, 0.75), mean differences were significantly smaller by 3DTEE than 2DTEE (-0.01 +/- 0.25 vs. -0.17 +/- 0.27 cm(2), P < 0.001). CONCLUSION Aortic annular motion affects the calculation of AVA using 2DTEE. Three-dimensional transoesophageal echocardiography has a potential for more accurate determination of anatomical AVA.

Effect of Through-Plane and Twisting Motion on Left Ventricular Strain Calculation: Direct Comparison between Two-Dimensional and Three-Dimensional Speckle-Tracking Echocardiography

BACKGROUND The aim of this study was to investigate the effect of out-of-plane motion on discrepancies in strain measurements between two-dimensional (2D) and three-dimensional (3D) echocardiography. METHODS Two-dimensional and 3D data sets were acquired in 54 patients. Using 2D and 3D speckle-tracking software, global circumferential strain (CS) and longitudinal strain (LS) as well as CS and LS at three left ventricular (LV) levels was measured. The effect of through-plane motion was assessed by mitral annular displacement. RESULTS Although a good correlation of global CS was noted between the two methods (r = 0.80, P < .01), mean values of global CS were significantly higher on 3D compared with 2D echocardiography. Correlations of CS and their mean differences were 0.65 and -4.61 at the basal level, 0.76 and -4.17 at the midventricular level, and 0.60 and -2.23 at the apical level, respectively. Correlation of global CS between the two methods was higher in patients who showed mitral annular displacement < 9.4 mm (r = 0.81) compared with those with mitral annular displacement ≥ 9.4 mm (r = 0.61). A good correlation of global LS (r = 0.89, P < .01) was noted, with no significant bias. Correlations of LS and their mean differences were 0.52 and 1.59 at the basal level, 0.89 and -1.17 at the midventricular level, and 0.73 and 1.46 at the apical level, respectively. Correlation of LS between the two methods was higher in patients who showed LV twist < 12.2° (r = 0.94) compared with patients with LV twist ≥ 12.2° (r = 0.68). CONCLUSIONS Through-plane motion produced discrepancies in CS measurements, especially at the LV basal level. Larger bias of LS at the basal and apical LV levels compared with the midventricular level between the two methods suggests that LV twisting also affects the calculation of 2D LS.

Continuous positive airway pressure ameliorates sleep-induced subclinical left ventricular systolic dysfunction: demonstration by two-dimensional speckle-tracking echocardiography

AIMS We hypothesized that continuous positive airway pressure (CPAP) therapy could improve sleep-induced left ventricular (LV) dysfunction in patients with obstructive sleep apnoea syndrome (OSA). The aim of this study was to investigate the effects of CPAP therapy on LV systolic dysfunction during overnight sleep in patients with OSA using two-dimensional speckle-tracking echocardiography (2DSTE). METHODS AND RESULTS 2D LV short-axis and apical views were acquired before and immediately after overnight sleeping in 32 patients with OSA and normal LV ejection fraction. Using 2D strain software, three-principal strains were measured. In a subset of 14 OSA patients who received chronic CPAP therapy, identical measurements were repeated 3 months after the therapy. Although no significant changes in global radial and circumferential strain were noted, global longitudinal strain was significantly reduced after overnight sleeping (-19.1 +/- 2.0) compared with before sleep (-20.7 +/- 1.8, P < 0.001). After CPAP therapy, improvements in apnoea-hypopnoea index and minimal oxygen saturation were accompanied by the disappearance of longitudinal strain reduction during overnight sleep. CONCLUSION Repetitive obstructive apnoea produces acute impairment of LV longitudinal function, suggesting the development of subendocardial ischaemia. CPAP therapy not only decreases the severity of OSA, but also ameliorates sleep-induced longitudinal LV dysfunction, which can be assessed by 2DSTE.

Evidence of a Vicious Cycle in Mitral Regurgitation With Prolapse Secondary Tethering Attributed to Primary Prolapse Demonstrated by Three-Dimensional Echocardiography Exacerbates Regurgitation

Background— In patients with mitral valve prolapse, nonprolapsed leaflets are often apically tented. We hypothesized that secondary left ventricular dilatation attributed to primary mitral regurgitation (MR) causes papillary muscle (PM) displacement, resulting in this leaflet tenting/tethering, and that secondary tethering further exacerbates malcoaptation and contributes to MR severity. Methods and Results— Three-dimensional transesophageal echocardiography was performed in 25 patients with posterior mitral leaflet prolapse with an intact anterior mitral leaflet (AML) and 20 controls. From 3D zoom data sets, 11 equidistant antero-posterior cut planes of the mitral valve at midsystole were obtained. In each plane, tenting area of nonprolapsed leaflet and prolapse area of prolapsed leaflet were measured. Prolapse/tenting volume of each region was obtained as the product of interslice distance and the prolapse/tenting area. AML tenting volume and whole leaflet prolapse/tenting volume were then obtained. The PM tethering distance between PM tips and anterior mitral annulus was measured from 3D full-volume data sets. The severity of MR was quantified by vena contracta area extracted from color 3D transesophageal echocardiography data sets. AML tenting volume was significantly larger in patients with posterior mitral leaflet prolapse compared with that in controls (1.2±0.5 versus 0.6±0.2 mL/m2; P<0.001). Multivariate regression analysis identified independent contribution to AML tenting volume from an increase in PM tethering distance. Multivariate regression analysis identified independent contributions to MR severity (vena contracta area) from both whole leaflet tenting volume (r=0.44; P<0.05) and prolapse volume (r=0.44; P<0.05). AML tenting volume decreased along with left ventricular volume and PM tethering distance postrepair (n=8; P<0.01). Conclusions— These results suggest that primary mitral valve prolapse with MR causes secondary mitral leaflet tethering with PM displacement by left ventricular dilatation, which further exacerbates valve leakage, constituting a vicious cycle that would suggest a pathophysiologic rationale for early surgical repair.

Arousal From Sleep and Sympathetic Excitation During Wakefulness

Obstructive apnea during sleep elevates the set point for efferent sympathetic outflow during wakefulness. Such resetting is attributed to hypoxia-induced upregulation of peripheral chemoreceptor and brain stem sympathetic function. Whether recurrent arousal from sleep also influences daytime muscle sympathetic nerve activity is unknown. We therefore tested, in a cohort of 48 primarily nonsleepy, middle-aged, male (30) and female (18) volunteers (age: 59±1 years, mean±SE), the hypothesis that the frequency of arousals from sleep (arousal index) would relate to daytime muscle sympathetic burst incidence, independently of the frequency of apnea or its severity. Polysomnography identified 24 as having either no or mild obstructive sleep apnea (apnea–hypopnea index <15 events/h) and 24 with moderate-to-severe obstructive sleep apnea (apnea–hypopnea index >15 events/h). Burst incidence correlated significantly with arousal index (r=0.53; P<0.001), minimum oxygen saturation (r=−0.43; P=0.002), apnea–hypopnea index (r=0.41; P=0.004), age (r=0.36; P=0.013), and body mass index (r=0.33; P=0.022) but not with oxygen desaturation index (r=0.28; P=0.056). Arousal index was the single strongest predictor of muscle sympathetic nerve activity burst incidence, present in all best subsets regression models. The model with the highest adjusted R2 (0.456) incorporated arousal index, minimum oxygen saturation, age, body mass index, and oxygen desaturation index but not apnea–hypopnea index. An apnea- and hypoxia-independent effect of sleep fragmentation on sympathetic discharge during wakefulness could contribute to intersubject variability, age-related increases in muscle sympathetic nerve activity, associations between sleep deprivation and insulin resistance or insomnia and future cardiovascular events, and residual adrenergic risk with persistence of hypertension should therapy eliminate obstructive apneas but not arousals.

Sleep-Disordered Breathing in Heart Failure ― A Therapeutic Dilemma ―

Sleep-disordered breathing (SDB) occurs in approximately 50% of patients with reduced left ventricular ejection fraction receiving contemporary heart failure (HF) therapies. Obstructive (OSA) and central sleep apneas (CSA) interrupt breathing by different mechanisms but impose qualitatively similar autonomic, chemical, mechanical, and inflammatory burdens on the heart and circulation. Because contemporary evidence-based drug and device HF therapies have little or no mitigating effect on the acute or long-term consequences of such stimuli, there is a sound mechanistic rationale for targeting SDB to reduce cardiovascular event rates and prolong life. However, the promise of observational studies and randomized trials of small size and duration describing a beneficial effect of treating SDB in HF via positive airway pressure was not realized in 2 recent randomized outcome-driven trials: SAVE, which evaluated the cardiovascular effect of treating OSA in a cohort without HF, and SERVE-HF, which reported the results of a strategy of random allocation of minute-ventilation-triggered adaptive servo-ventilation (ASV) for HF patients with CSA. Whether effective treatment of either OSA or CSA improves the HF trajectory by reducing cardiovascular morbidity or mortality has yet to be definitively established. ADVENT-HF, designed to determine the effect of treating both CSA and non-sleepy OSA HF patients with a peak-airflow triggered ASV algorithm, could resolve this present clinical equipoise concerning the treatment of SDB.

Immediate Amelioration of Mechanical Pulsus Alternans by Adaptive Servo-ventilation Therapy

echanical pulsus alternans is sometimes seen inpatients with severe heart failure. This case reportdescribes a patient with medically refractory acute heartfailure due to severe left ventricular (LV) systolic dys-function withpulsusalternans,whereshort-termadaptiveservo-ventilation (ASV)therapyimmediatelyamelioratedthe mechanical pulsus alternans.A 52 year-old male was admitted to the hospitaldue to progressive exertional dyspnoea. Auscultationof the chest revealed fine crackles over both lungs.An S3 gallop rhythm and a grade 2/6 of pansystolicmurmur were audible at the apex. His blood pres-sure was 110/70mmHg and heart rate was 120bpm.Chest X ray showed cardiomegaly with bilateral pul-monary congestion. The electrocardiogram showed sinustachycardia with normal QRS duration. Blood exami-nation on admission revealed remarkable elevation inthe serum level of brain natriuretic peptide (BNP) of1740 pg/dl (<18.4pg/ml). Echocardiography showed aseverely dilated left ventricle (LV) with an ejection frac-tion of 15% (Movie 1). Estimated systolic pulmonaryartery pressure from tricuspid regurgitation velocity was64 mmHg. Initial treatment with angiotensin II recep-tor blockers, intravenous diuretics, and carperitide failedto provide a favourable response. Subsequently, intra-venous phosphodiesterase III inhibitor for three daysdid not improve his condition. Radial pulse revealedalternating strong and weak beats, indicating mechanicalpulsus alternans. Repeated echocardiography demon-strated alternating pulsed Doppler flow velocities acrossthe LV outflow tract (LVOT) with no significant change ofLV size and systolic function compared to the previousstudy (Fig. 1). Although oxygen saturation was preservedby