Mitral Annular Disjunction-A New Disease Spectrum.

Mitral annular disjunction is a structural abnormality of the mitral annulus fibrosus, which has been described by pathologists to be associated with mitral leaflet prolapse. Mitral annular disjunction is a common finding in patients with myxomatous mitral valve diseases. The prevalence of mitral annular disjunction should be checked routinely during presurgical imaging. Otherwise, mitral annular disjunction itself might be an arrhythmogenic entity, irrespective of the presence of mitral valve prolapse (MVP). Therefore, we should check echocardiography keeping in mind mitral annular disjunction. Further prospective studies are needed to address whether a causative mechanistic link exists between mitral annular disjunction and arrhythmic MVP.

Mitral annular disjunction in patients with primary severe mitral regurgitation and mitral valve prolapse.

BACKGROUND: Mitral annular disjunction is a structural abnormality of the mitral annulus fibrosus which is often associated with mitral leaflet prolapse. However, few reports have described mitral annular disjunction in mitral valve prolapse (MVP). This study aimed to investigate the characteristics of mitral annular disjunction in patients with severe mitral regurgitation (MR) caused by MVP. METHODS: We reviewed 185 consecutive patients with severe MR caused by fibroelastic deficiency (FED) and Barlow's syndrome from March 2009 to December 2010. The upper limit of the disjunction was defined at the level of the posterior scallop's insertion into the left atrial wall, whereas the lower limit was defined at the level of the left atrium's connection to the ventricular myocardium. The distance between the two levels was called mitral annular disjunction. Prolapse sites in FED patients were categorized into anterior leaflet, posterior leaflet, and commissure groups. Patients with a disjunction distance of ≥2 mm were diagnosed with mitral annular disjunction. RESULTS: Annular disjunction was found in 45 patients (24%). Among them, the most common site of prolapse was the posterior leaflet (n = 35, 77.8%). During a median follow-up of 20.3 years, arrhythmic events and sudden death occurred in seven patients (3.8%). CONCLUSIONS: Mitral annular disjunction was detected in 24% of patients with severe MR and in 90% of the patients with Barlow's syndrome. There were significant differences at its sites of prolapse in FED patients. The presence and site of prolapse with mitral annular disjunction should be actively determined in FED patients.

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

AIMS: 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). METHODS AND RESULTS: Of the 237 consecutive patients who showed left ventricular hypertrophy (LVH) pattern on a 12-lead ECG, TTE data were available for 101 patients. The patients were divided into the two groups according to the presence (ECG-LVH [strain pos] group, n = 60) or absence (ECG-LVH [strain neg] group, n = 41) of LV strain pattern (study 1). The prevalence of papillary muscle hypertrophy using TTE was significantly higher in the ECG-LVH (strain neg) group than in the ECG-LVH (strain pos) group (P = .0002). Of the 42 cases with papillary muscle hypertrophy, 5 cases (12%) showed isolated papillary muscle hypertrophy with normal geometry. ECG data were prospectively analyzed for 36 patients who were diagnosed with papillary muscle hypertrophy by TTE (study 2). The prevalence of LV strain pattern was significantly higher in patients with LV wall hypertrophy than in those without LV wall hypertrophy (P = .04). Of the 25 cases with papillary muscle hypertrophy, 6 cases (24%) showed normal geometry and 4 cases (16%) showed ECG abnormality. CONCLUSIONS: Isolated papillary muscle hypertrophy can cause ECG abnormalities such as LV high voltage and LV strain pattern. Particular attention must be paid to the papillary muscle during echocardiographic examinations.

Primary and metastatic cardiac tumors: echocardiographic diagnosis, treatment and prognosis in a 15-years single center study.

BACKGROUND: The frequency of primary cardiac tumors is rare at about 0.3% by autopsy. Our objective was to investigate the characteristics and locations of cardiac tumors and to provide a prognostic analysis in our hospital. METHODS: We collected data on 95 patients with echocardiographic diagnosis or detection of cardiac tumors in a prospective analysis from 1999 to 2014. The median follow-up period was 43 months (0.5-183 months). RESULTS: The subjects included 56 men and 39 women with a mean age of 65 years. Clinical diagnosis revealed primary tumors in 61 patients (64%) and secondary metastatic tumors in 34 patients (36%). In the 61 patients, 41 patients (67%) underwent surgery and tissue samples were obtained. Of these 41 patients, benign tumors were found in 30 cases (73%). One patient (2%) was diagnosed with thrombus. Among the benign tumors, myxoma (67%) was the most common type followed by papillary fibroelastoma (23%). The most common site was the left atrium (35%) followed by the right atrium (25%). Primary malignant tumors were diagnosed in 10 cases (24%), including 6 angiosarcomas, 3 lymphomas, and 1 leiomyosarcoma. The diagnostic accuracy of echocardiography was 80%. The patients with benign tumors were all alive at the end of the follow-up period. In contrast, 7 patients with malignant tumors died (70%) (p < 0.0001). CONCLUSIONS: Our data is in line with previous literature. Our study also suggests the necessity of extending our knowledge of the characteristics of cardiac tumors for diagnosis.

The analysis of mitral annular disjunction detected by echocardiography and comparison with previously reported pathological data.

BACKGROUND: Mitral annular disjunction is a structural abnormality of the mitral annulus fibrosus and is pathologically defined by a separation between the atrial wall-mitral valve junction and the left ventricular attachment. Mitral annular disjunction can cause hypermobility of the mitral valve apparatus and is often associated with mitral valve prolapse (MVP). The aim of this study was to investigate the frequency and characteristics of mitral annular disjunction in the patients referred to an echocardiography laboratory and to compare these with previously reported pathological data. METHODS AND RESULTS: We retrospectively studied 1439 patients (mean age 65 ± 17 years, 58% male) referred to our echocardiography laboratory from 6 January 2014 to 31 March 2014. The echocardiographic parameters were compared between the patients with and without mitral annular disjunction. There were 125 cases (8.7%) with mitral annular disjunction, of which 15 (12%) also had MVP. The number of MVP patients in the group with mitral annular disjunction was significantly larger than in the group without mitral annular disjunction (p < 0.0001). The grade of mitral regurgitation was not significantly different between the two groups. CONCLUSIONS: Mitral annular disjunction was detected not only in patients with a myxomatous mitral valve but also in normal cases. The number of MVPs was significantly larger in patients with mitral annular disjunction than patients without mitral annular disjunction. Further investigation is needed to clarify the clinical significance of the mitral annular disjunction detected by routine echocardiography.

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

AIMS: To prospectively evaluate the relationship between left atrial volume (LAV) and the risk of clinical events in patients with hypertrophic cardiomyopathy (HCM). METHODS: We 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. RESULTS: MACCE 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%. CONCLUSION: LAVI may be an effective marker for detecting the risk of MACCE in patients with HCM and normal pump function.

[Left ventricular volume and ejection fraction by the axius auto ejection fraction method: comparison with manual trace method and visual assessment of ejection fraction].

OBJECTIVES: Visual assessment of the ejection fraction (EF) is often used in clinical practice, but is subjective and requires training and experience. The auto EF method has been newly developed for automated detection of the left ventricular (LV) endocardial border throughout the cardiac cycle. The clinical feasibility was assessed of the auto EF method for measuring LV volumes and EF in patients. Manually traced EF measured by the biplane modified Simpson's rule was used as the reference standard. METHODS: The study population consisted of 30 consecutive patients with normal sinus rhythm. All patients underwent two-dimensional echocardiography. The auto EF method incorporated pattern and shape recognition to automatically locate the LV, track the endocardium, and calculate EF from routine digital images. LV end-diastolic and end-systolic volumes and EF measured by the auto EF method were compared those by the manually traced method. LVEF by the Auto EF method was also compared with visual EF determined by nonattending physicians. RESULTS: Auto EF was more reproducible than visual EF by the expert reader. LVEF by the auto EF method had excellent correlation and close limits of agreement with manually traced EF compared with visual EF(4-chamber view: y = 1.10 x - 4.28, r = 0.94, bias = 1.6%, 2-chamber view: y = 0.88 x + 7.25, r = 0.90, bias = 0.4%). LV volumes by the auto EF method underestimated those by manually traced EF (end-diastolic volume by 4-chamber view: y = 0.72 x + 8.92, r = 0.93, bias = - 16.7 ml, end-systolic volume by 4-chamber view: y = 0.82 x - 0.97, r = 0.98, bias = - 8.5 ml, end-diastolic volume by 2-chamber view: y = 0.73 x + 12.4, r = 0.82, bias = - 12.3 ml, end-systolic volume by 2-chamber view: y = 0.65 x + 6.94, r = 0.90, bias = - 6.8 ml). CONCLUSIONS: The auto EF method is a clinically useful tool for the measurement of LV volumes and EF.

Left atrial volume in normal Japanese adults.

BACKGROUND: Two-dimensional (D) echocardiography-derived left atrial (LA) volume has been shown to provide a more accurate assessment of LA size than the M-mode LA dimension. Our objective was to provide reference ranges of LA volume in healthy Japanese adults. METHODS AND RESULTS: The study subjects consisted of 105 Japanese adults, with a mean age of 39+/-13 years (range 20-63 years old). All subjects had normal ejection fraction (>55%), no wall motion abnormalities, normal diastolic function, no valvular disease, and normal sinus rhythm. The maximum LA volume, at left ventricular end-systole just before the opening of the mitral valve, was measured by using the bi-apical (4- and 2-chamber views) Simpson's rule. Both the absolute LA volume and the volume corrected by body surface area (LA volume index) were obtained. The LA volume ranged from 21 to 53 ml (mean 37+/-8 ml) and the LA volume index ranged from 13 to 30 ml/m(2) (mean 22+/-4 ml/m(2)). The mean LA volume index + 2SDs was 30 ml/m(2). CONCLUSIONS: Recognition of the upper limits of LA volume in normal Japanese subjects is of particular clinical relevance because it offers the opportunity of pathological LA remodeling diagnosis.

Left atrial volume and the risk of paroxysmal atrial fibrillation in patients with hypertrophic cardiomyopathy.

Paroxysmal atrial fibrillation (PAF) is a common complication of patients with hypertrophic cardiomyopathy, often leading to acute or progressive heart failure and cerebral infarction. We assessed the echocardiographic data of 141 consecutive patients with hypertrophic cardiomyopathy, with and without PAF. In all, 31 patients (22%) had a history of PAF with spontaneous conversion to in sinus rhythm. Left atrial volume and left atrial volume indexed to body surface area were significantly increased for patients with PAF compared with those without PAF. Maximum left atrial volume was the most sensitive and specific parameter for the occurrence of PAF in patients with hypertrophic cardiomyopathy.

[Validation of a new hand-carried ultrasound device equipped with directional color power Doppler and continuous wave Doppler].

OBJECTIVES: This study evaluated the accuracy of the directional color power Doppler (DCPD) and continuous wave Doppler (CWD) methods incorporated in the new hand-carried SonoSite 180PLUS ultrasound device. METHODS: The hand-held ultrasound system with 2.5 MHz transducer and SONOS 5500 was used as a standard ultrasound system with a 2 to 4 MHz wideband transducer. The experimental study used a Doppler wire phantom to evaluate the influence of target wire speed and angle of transducer on DCPD imaging. The clinical study included 48 consecutive patients. DCPD assessment of valvular regurgitation measured the distances of DCPD signals of mitral, aortic and tricuspid valve regurgitation using the apical four-chamber view for comparison with standard echocardiography. CWD assessment measured the peak velocities of the aortic flow and tricuspid valve regurgitant flow for comparison with standard echocardiography. RESULTS: In the experimental study, DCPD signals were not influenced by target wire speed changes and transducer incident angles. In the clinical study, agreements for mitral, aortic and tricuspid regurgitation between the two methods were 89.6%, 81.8% and 78.7%, respectively. The distances of DCPD valve regurgitant signals by the hand-carried ultrasound device showed good correlation (mitral regurgitation: y = 0.84x + 0.55; r = 0.93, aortic regurgitation: y = 0.95x + 0.27; r = 0.94, tricuspid regurgitation: y = 0.86x + 0.61; r = 0.90) with those by standard echocardiography. Evaluation of CWD velocity measurements showed good agreement for the lower flow velocities (< 2.0 m/sec). However, underestimation occurred for the high flow velocities (> 2.0 m/sec) compared with those by standard echocardiography (aortic flow: y = 0.80x + 0.11; r = 0.95, tricuspid regurgitation: y = 1.00x - 0.23; r = 0.90). CONCLUSIONS: The new hand-carried ultrasound device (SonoSite 180PLUS equipped with DCPD and CWD) is clinically useful for evaluating valvular regurgitations and flow velocities. Further studies are needed to determine the mechanism of the underestimation of high flow velocities by CWD.

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.

[Assessment of the clinical feasibility of OptiGo for hand-held echocardiography].

OBJECTIVES: Hand-held ultrasound devices are becoming available for clinical examination, but the accuracy and precision of such devices are unclear. This study compared the accuracy of a hand-held echo device to a standard echo system. METHODS: Twenty-two patients were examined with the OptiGo (Phillips Medial Systems) hand-held ultrasound system with a 2.5 MHz transducer and SONOS 5500 (Phillips Medial Systems) standard ultrasound system with a 2 to 4 MHz wideband transducer. Patients with cardiac arrhythmia and tachycardia were excluded. Image quality, chamber size (left ventricle, left atrium), global and regional left ventricular function, valve morphology and severity of valve regurgitation were assessed. RESULTS: There was good agreement between the two imaging devices for image quality (77.3%), left ventricular ejection fraction (90.5%), regional wall motion score (> 90%), valve morphology (> 90%), severity of valve regurgitation (> 81.0%) and there was good correlation and agreement for left ventricular and left atrial size. CONCLUSIONS: Although the OptiGo has limitations, the hand-held examination appropriately estimates global and regional left ventricular function, valve morphology, valve regurgitation and chamber size.

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.