Kazuto Yamaguchi

Single-beat Determination of Doppler-derived Aortic Flow Measurement in Patients with Atrial Fibrillation

The clinical assessment of left ventricular systolic function in patients with atrial fibrillation is unreliable and difficult because of beat-to-beat variation. We initially evaluated an index that is on the basis of the ratio of preceding R-R (RR1) to pre-preceding R-R (RR2) intervals (RR1/RR2) for the measurement of Doppler aortic flow (peak flow velocity [Vp] and time-velocity integral [TVI] proportional to stroke volume) in 20 patients (aged 65 +/- 9.6 years) with atrial fibrillation. We obtained each parameter for >13 cardiac cycles, and the relationship between each parameter at a given cardiac beat and the RR1/RR2 ratio were evaluated by linear regression analysis. The value of each parameter at RR1/RR2 = 1 was calculated from the equation of linear regression line and compared with measured average value over all cardiac cycles. Both parameters showed a significant positive correlation with the RR1/RR2 ratio (Vp, r = 0.98, y = 1.01x + 0.61; TVI, r = 0.99, y = 1.01x + 0.26). The calculated value of each parameter at RR1/RR2 = 1 was quite similar to the average value (Vp, 97.4 +/- 30.8 vs 95.7 +/- 29.8 cm/s; TVI, 17.7 +/- 6.8 vs 17.3 +/- 6.7 cm, respectively). In the additional 20 patients (aged 77.4 +/- 15.2 years), Doppler aortic flow parameters of a single beat with identical RR1 and RR2 intervals were compared with measured average value over all cardiac cycles and showed similar results (Vp, r = 0.99, y = 0.99x + 3.4, P <.0001, bias -0.5 cm/s; TVI, r = 0.99, y = 0.92x + 1.5, P <.0001, bias 0.1 cm). In conclusion, the Doppler aortic flow at RR1/RR2 = 1 allows the left ventricular systolic parameters to be accurately evaluated during atrial fibrillation and obviates the less reliable process of averaging multiple irregular beats.

Left Ventricular Systolic Dyssynchrony Index by Three‐Dimensional Echocardiography in Patients with Decreased Left Ventricular Function: Comparison with Tissue Doppler Echocardiography

Background: Three‐dimensional echocardiography (3DE) can simultaneously assess left ventricular (LV) regional systolic motion and global LV mechanical dyssynchrony. Methods: We used 3DE to measure systolic dyssynchrony index (SDI) (standard deviation of the time from cardiac cycle onset to minimum systolic volume in 17 LV segments) in 100 patients and analyzed the association of SDI with other parameters for LV systolic function or dyssynchrony. Eighteen patients who underwent cardiac resynchronization therapy (CRT) were also evaluated at 6 months after CRT, and the association of baseline SDI and tissue Doppler imaging (TDI) dyssynchrony index (Ts‐SD) with the change of LV end‐systolic volume (ESV) analyzed. Ts‐SD was calculated using the standard deviation of the time from the QRS complex to peak systolic velocity. Results: There was a significant inverse correlation between LVEF and SDI (r =−0.686, P < 0.0001). QRS duration was also significantly correlated to SDI (r = 0.407, P < 0.0001). There was a significant positive correlation between baseline SDI and the decrease in LVESV after CRT (r = 0.42). Baseline SDI was significantly greater in responders (10 patients) than in nonresponders (16.4 ± 5.1 vs. 7.9 ± 2.4%, P < 0.01), but there was no significant difference in Ts‐SD. SDI > 11.9% predicted CRT response with a sensitivity of 90% and a specificity of 75%. Conclusions: SDI derived from 3DE is a useful parameter to assess global LV systolic dyssynchrony and predict responses to CRT. (Echocardiography 2012;29:346‐352)

Factors influencing left atrial volume in treated hypertension

BACKGROUND Left atrial (LA) enlargement has been documented to occur in hypertension (HT), and has been an index for evaluating the diastolic function of the left ventricle. Enlargement of the LA is one of the vital factors that induce heart failure and atrial fibrillation (AF) in patients with HT. METHODS AND SUBJECTS 130 treated hypertensive patients were enrolled. All recruits participated in an echocardiogram, electrocardiogram, a routine blood examination including brain natriuretic peptide (BNP), and physical examinations. RESULTS Left ventricular mass (LVM) indexed to height(2.7) had a significant positive correlation with left atrial volume index (LAVI) (p<0.0001), as well as natural logarithm BNP (p<0.001). Blood pressure levels were not associated with LAVI, neither body mass index nor age. LAVI had a positive correlation with factors involving the left ventricle volume, LVM, and right ventricle systolic pressure (RVSP) (r=0.687, p<0.0001). The parameters of LV diastolic function were positively but weakly associated with LA size. In the subgroup of LAVI, the evidence of paroxysmal atrial fibrillation (PAF): LAVI<32 ml/m(2) had no PAF, whereas the incidence of PAF was 7.5%, 11.4%, and 15.2%, respectively in the LAVI>32 ml/m(2) group. Of anti-hypertension drugs, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers had a tendency to reduce LAVI; however, there was no statistical significance within the groups. CONCLUSIONS Left ventricular volume and mass are independent factors affecting LAVI in treated HT. The incidence of PAF is associated with LA size. In patients with treated HT, LA size may be a useful surrogate marker for monitoring the effectiveness of medical therapy and occurrence of AF.

Left Atrial Remodeling and Recurrence of Congestive Heart Failure in Patients Initially Diagnosed with Heart Failure

Left atrial volumes (LAVs) have been suggested to represent long‐term exposure to elevated pressures. This study examined the recurrence of heart failure (HF) based on LAV in patients initially diagnosed with congestive HF (CHF).

A case of myocardial infarction and left ventricular pseudo-false aneurysm perforating the right ventricle

We describe a case of left ventricular (LV) pseudo-false aneurysm perforating the right ventricle (RV), which is a very uncommon complication of myocardial infarction (MI). An 88-year-old woman was referred to our hospital because of complete atrioventricular block. She was drowsy, her heart rate was 27 beats/min, and her blood pressure was 90/70 mmHg. A grade of II/VI pansystolic murmur was audible at the lower sternal border. Echocardiographic study revealed an aneurysm on the inferoseptum and a large (30 mm) defect between the inferoseptal wall and the aneurysm (Fig. 1a). A color Doppler image showed shunt flows passing from a large defect of inferoseptal myocardium and the aneurysmal pouch to the RV (Fig. 1b, c). Coronary arteriography was performed and the proximal right coronary artery (RCA) was occluded. The left coronary arteries were normal and percutaneous coronary intervention of the RCA was not performed. On the basis of the initial laboratory examination findings (creatine kinase 563 U/L, creatine kinase MB 29.1 ng/mL, troponin I 49.31 ng/mL), she was diagnosed with a perforation of an LV pseudo-false aneurysm into the RV following the subacute phase of an inferior MI. Temporary pacing and intra-aortic balloon pumping were started, and prompt surgical repair of the LV pseudo-false aneurysm was considered. However, her operative risk was high and her family desired conservative management. She died 10 days after admission as a result of multi-organ failure. An LV pseudo-false aneurysm, which was first reported by Stewart et al. [1], is a very uncommon complication of MI. It occurs when hemorrhagic dissection into the area of a transmural MI does not completely reach the epicardium and is contained within the area of the infarcted myocardium. Several authors described the perforation of an LV pseudo-false aneurysm into the RV following acute inferior MI [2, 3]. Although the hemodynamics of this condition are similar to those of postinfarction ventricular septal defect, the perforation usually develops in the subacute or chronic phase of MI. Although no pathology examination was performed, the present patient was diagnosed as having an LV pseudo-false aneurysm on the basis of echocardiographic findings of incompletely dissected myocardium and the aneurysmal pouch containing the area

Factors Influencing the Prognosis of Octogenarians with Aortic Stenosis in the Advanced Aging Societies

Objective The recognition of clinical symptoms is critical to developing an effective therapeutic strategy for aortic valve stenosis (AS). Although AS is common, little is known about the factors influencing the natural history of AS patients who are 80 years of age older in advanced aging societies. We investigated the natural history and indications for valve procedures in AS patients of 80 years of age or older. Methods The medical records of 108 consecutive AS patients (moderate grade or higher) who are 80 years of age or older (mean age, 84.2±3.9 years; female, 65 patients) were reviewed to investigate their symptoms, the development of congestive heart failure, the incidence of referral for aortic valve replacement and death. The median duration of follow-up was 9 months (interquartile range, 2 to 25 months). Results The probability of remaining free of events (valve replacement and death) was 29±13% in all patients. There was no significant difference in the aortic valve area of the symptomatic and asymptomatic patients (0.85±0.28 cm(2) vs. 0.88±0.25 cm(2), p=0.59). The aortic valve (AV) velocity and AV area index were predictors of subsequent cardiac events (p<0.05). Conclusion The severity of AS was the only factor to affect the prognosis of AS patients who were 80 years old of age or older. It is necessary to frequently monitor the subjective symptoms of such patients and to objectively measure the AV area.

Visually confirmed post-systolic shortening during the recovery period in four cases of Takotsubo cardiomyopathy

We report visually confirmed post-systolic shortening (PSS) during the recovery period and the relationship between PSS and electrocardiographic abnormalities in 4 cases of Takotsubo cardiomyopathy (TTC). In these 4 cases, the appearance of visually confirmed PSS during the recovery period coincided with observation of the deepest T wave and the longest QT interval. The transmural repolarization gradient and heterogeneous duration of myocardial contractions may cause PSS in the TTC recovery period.