Junichi Kawai

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 atrial volume predicts adverse cardiac and cerebrovascular events in patients with hypertrophic cardiomyopathy

AimsTo prospectively evaluate the relationship between left atrial volume (LAV) and the risk of clinical events in patients with hypertrophic cardiomyopathy (HCM).MethodsWe enrolled a total of 141 HCM patients with sinus rhythm and normal pump function, and 102 patients (73 men; mean age, 61 ± 13 years) who met inclusion criteria were followed for 30.8 ± 10.0 months. The patients were divided into two groups with or without major adverse cardiac and cerebrovascular events (MACCE), a composite of stroke, sudden death, and congestive heart failure. Detailed clinical and echocardiographic data were obtained.ResultsMACCE occurred in 24 patients (18 strokes, 4 congestive heart failure and 2 sudden deaths). Maximum LAV, minimum LAV, and LAV index (LAVI) corrected for body surface area (BSA) were significantly greater in patients with MACCE than those without MACCE (maximum LAV: 64.3 ± 25.0 vs. 51.9 ± 16.0 ml, p = 0.005; minimum LAV: 33.9 ± 15.1 vs. 26.2 ± 10.9 ml, p = 0.008; LAVI: 40.1 ± 15.4 vs. 31.5 ± 8.7 ml/mm2, p = 0.0009), while there were no differences in the other echocardiographic parameters.LAV/BSA of ≥ 40.4 ml/m2 to identify patients with cardiovascular complications with a sensitivity of 73% and a specificity of 88%.ConclusionLAVI may be an effective marker for detecting the risk of MACCE in patients with HCM and normal pump function.

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)

Significance of isolated papillary muscle hypertrophy: A comparison of left ventricular hypertrophy diagnosed using electrocardiography vs echocardiography

The clinical significance of papillary muscle hypertrophy and its electrocardiography (ECG) findings has not been fully elucidated. This study aimed to investigate the relationship between ECG findings and papillary muscle hypertrophy and to confirm the importance of papillary muscle measurements on transthoracic echocardiography (TTE).

Pulsed Doppler echocardiographic detection of the origin of musical murmurs in a case of pacemaker implantation.

We report a case of systolic and diastolic musical murmurs that developed 4 years after DDD pacemaker implantation. Echocardiographic examination disclosed no evidence of serious pacemaker-related complications. Pulsed Doppler examination with a sample volume at the right ventricular portion of a pacemaker lead showed prominent harmonic signals. The timing of the signals was consistent with that of musical murmurs. We considered vibration of the pacemaker lead as a possible origin of the musical murmurs. Systolic and diastolic musical murmurs can develop without serious cause in a patient with a transvenous pacemaker. Pulsed Doppler examination was useful in detecting the origin of musical murmurs.