Chiharu Tanaka

A Novel and Simple Method Using Pocket-Sized Echocardiography to Screen for Aortic Stenosis

BACKGROUND Pocket-sized echocardiography may serve as an initial tool to screen for aortic stenosis (AS). The purpose of this study was to evaluate the usefulness of a novel and simple method using pocket-sized echocardiography to screen for AS. METHODS Subjects (n= 130) with systolic ejection murmur or known AS were studied. After physical examination, each aortic cusps opening was visually scored using pocket-sized echocardiography as follows: 0= not restricted, 1= restricted, or 2= severely restricted. The sum of the scores was defined as the visual AS score. On the basis of high-end echocardiography, an aortic valve area index <0.60 cm(2)/m(2) and an aortic valve area index of 0.60 to 0.85 cm(2)/m(2) were considered to indicate severe and moderate AS, respectively. RESULTS For diagnosing severe AS (n= 27), a visual AS score ≥ 4 had sensitivity of 85% and specificity of 89%. For diagnosing moderate to severe AS (n= 57), a visual AS score ≥ 3 had sensitivity of 84% and specificity of 90%. The areas under the receiver operating characteristic curves for diagnosing severe and moderate to severe AS with a visual AS score (0.946 and 0.936, respectively) were slightly larger than those for a skilled physical examination (0.917 and 0.898, respectively) (P= NS for both) but were significantly larger than for an aortic valve calcification score also obtained using pocket-sized echocardiography (areas under the curve, 0.816 [P= .0015] and 0.827 [P= .0001], respectively). CONCLUSIONS A novel and simple method using pocket-sized echocardiography is useful for rapid grading of AS in subjects with systolic ejection murmur.

Comparison of two-dimensional and real-time three-dimensional transesophageal echocardiography in the assessment of aortic valve area

BACKGROUND The accuracy of two-dimensional transesophageal echocardiography (2D-TEE) for the measurement of aortic valve area (AVA) in patients with aortic stenosis (AS) depends upon the cross-section selected for imaging. Real-time three-dimensional transesophageal echocardiography (3D-TEE) may overcome this limitation of 2D-TEE. The goal of this study was to compare 3D-TEE with 2D-TEE for the measurement of AVA. METHODS AND RESULTS Twenty-five patients with AS underwent TEE. In 2D-TEE, the aortic valve image was obtained at the orifice level in the short-axis view, and AVA was measured by planimetry of the acquired images (2D-AVA). In 3D-TEE, 3D data containing the entire aortic valve were obtained. Then, a short-axis cross-section containing the smallest orifice in mid-systole was cut from the 3D data during image postprocessing, and the AVA was measured by planimetry (3D-AVA). The 3D-AVA was significantly smaller than the 2D-AVA (0.79±0.35cm(2) vs. 0.93±0.40cm(2), p<0.0001), but there was a strong correlation between 3D-AVA and 2D-AVA (R=0.94). Although the frame rate was lower in 3D-TEE than in 2D-TEE (17±6Hz vs. 58±16Hz), the 3D-AVA determined at each frame during systole showed that the difference between 3D-AVA and 2D-AVA was not explained by the lower frame rate. The time required for image acquisition of the aortic valve was shorter with 3D-TEE than with 2D-TEE (p=0.0005). CONCLUSIONS The geometric AVA is smaller with 3D-TEE than with 2D-TEE, and the difference is not due to the lower frame rate of 3D-TEE. The improved accuracy of 3D-TEE along with reduced image acquisition time indicates that 3D-TEE is superior to 2D-TEE for the assessment of AVA.

Features of intrinsic ganglionated plexi in both atria after extensive pulmonary isolation and their clinical significance after catheter ablation in patients with atrial fibrillation

BACKGROUND The features of intrinsic ganglionated plexi (GP) in both atria after extensive pulmonary vein isolation (PVI) and their clinical implications have not been clarified in patients with atrial fibrillation (AF). OBJECTIVE The purpose of this study was to assess the features of GP response after extensive PVI and to evaluate the relationship between GP responses and subsequent AF episodes. METHODS The study population consisted of 216 consecutive AF patients (104 persistent AF) who underwent an initial ablation. We searched for the GP sites in both atria after an extensive PVI. RESULTS GP responses were determined in 186 of 216 patients (85.6%). In the left atrium, GP responses were observed around the right inferior GP in 116 of 216 patients (53.7%) and around the left inferior GP in 57 of 216 (26.4%). In the right atrium, GP responses were observed around the posteroseptal area: inside the CS in 64 of 216 patients (29.6%), at the CS ostium in 150 of 216 (69.4%), and in the lower right atrium in 45 of 216 (20.8%). The presence of a positive GP response was an independent risk factor for AF recurrence (hazard ratio 4.04, confidence interval 1.48-11.0) in patients with paroxysmal, but not persistent, AF. The incidence of recurrent atrial tachyarrhythmias in patients with paroxysmal AF with a positive GP response was 51% vs 8% in those without a GP response (P = .002). CONCLUSION The presence of GP responses after extensive PVI was significantly associated with increased AF recurrence after ablation in patients with paroxysmal AF.

Residual arrhythmogenic foci predict recurrence in long-standing persistent atrial fibrillation patients after sinus rhythm restoration ablation.

BACKGROUND The mechanism of persistent atrial fibrillation (AF) is multifactorial, and arrhythmogenic foci (AMF) might be involved in the occurrence of persistent AF. In this study, we examined the electrophysiological features of AMF during and immediately after ablation, and evaluated the relationship between the presence and number of residual AMF on the risk of AF recurrence after a vigorous sinus rhythm restoration ablation in patients with long-standing persistent AF. METHODS The study consisted of 117 consecutive patients with persistent AF who underwent catheter ablation (CA). We performed direct cardioversion to restore sinus rhythm before the pulmonary vein (PV) isolation and at the end of the CA. Then we evaluated the features of the AMF inducible with isoproterenol and the pacing-based AF inducibility. RESULTS After the completion of ablation, AF could still be induced in 37 of 117 patients (31.6%). Spontaneous PV AMF during CA were observed in 104 of 117 patients (91%), and non-PV AMF in 63 of 117 (54%). Residual non-PV AMF were significantly associated with the pacing-based AF inducibility and an enlarged left atrial volume. In the multivariate analysis, the AF duration (1.01 [range, 1.00-1.02] months; P = 0.012), left atrial volume (1.01 [range, 1.01-1.02] mm; P = 0.006), and residual AMF (3.95 [range, 1.32-11.8] yes, no; P = 0.004) were independent risk factors for recurrent AF. CONCLUSIONS Residual AMF are associated with an increased long-term AF recurrence after sinus rhythm restoration ablation for long-standing persistent AF.

Real-time transesophageal echocardiography facilitates antegrade balloon aortic valvuloplasty.

We report two cases of severe aortic stenosis (AS) where antegrade balloon aortic valvuloplasty (BAV) was performed under real-time transesophageal echocardiography (TEE) guidance. Real-time TEE can provide useful information for evaluating the aortic valve response to valvuloplasty during the procedure. It was led with the intentional wire-bias technique in order to compress the severely calcified leaflet, and consequently allowed the balloon to reach the largest possible size and achieve full expansion of the aortic annulus.

Prediction of aortic stenosis-related events in patients with systolic ejection murmur using pocket-sized echocardiography

BACKGROUND We have previously reported the usefulness of our newly developed visual aortic stenosis (AS) score in screening for AS using pocket-sized echocardiography. The objective of this study was to investigate whether the visual AS score and/or conventional aortic valve calcification score derived from pocket-sized echocardiography can be used to predict AS-related events. METHODS One hundred and nine patients with systolic ejection murmur (SEM) or known AS (64 males, age 75±9 years) were enrolled and a visual AS score and an aortic valve calcification score were assessed using pocket-sized echocardiography. The primary endpoint was defined as AS-related events, including cardiac death and aortic valve replacement, during the follow-up period. RESULTS In a multivariate Cox proportional hazards analysis, AS-related events were independently predicted by an aortic valve calcification score ≥3 (HR, 3.5; 95% CI, 1.1-11; p=0.033) and a visual AS score ≥3 (HR, 15; 95% CI, 1.8-125; p=0.013). During 18±9 months of follow-up, the event-free survival rate was 98% in patients with both a visual AS score <3 and an aortic valve calcification score <3, 90% in patients with either a visual AS score ≥3 or an aortic valve calcification score ≥3 (p<0.0001), and 62% in patients with both a visual AS score ≥3 and an aortic valve calcification score ≥3 (p<0.0001). CONCLUSIONS The combination of visual AS score and aortic valve calcification score derived from pocket-sized echocardiography is useful for predicting AS-related events in patients with SEM.

Preferential Conduction Properties Along The Left Lateral Ridge And The Arrhythmogenicity Of The Left Pulmonary Veins In Patients With Atrial Fibrillation

PURPOSE In this study, we examined the hypothesis that the preferential conduction property along left lateral ridge (LLR) might affect the arrhythmogenicity of left pulmonary veins (LPVs). METHODS The study population included 40 consecutive AF patients. Radiofrequency energy (RF) was sequentially delivered along the LLR from a lower to upper manner during postero-lateral CS pacing during an isoproterenol infusion. RESULTS The conduction time during pacing from the CS was significantly prolonged during radiofrequency (RF) deliveries (before vs. after, upper; 91±26ms vs. 127±38ms, p<0.001, lower; 86±21ms vs. 103±22ms, p<0.001). Remarkable prolongation of more than 30ms was observed in 19 of 40 patients (48%) (both LPVs, 6; only the upper LPVs, 12; and only the lower LPV, 1). Sites with a remarkable prolongation were observed at the carina between the LPVs,[4] anterior site of the upper LPV carina,[10] anterior wall of the lower LPV,[3] and bottom of the lower LPVs [2] Thirty-three arrhythmogenic foci (AMF) from the LPVs were observed in 23/40 patients (56%). The conduction time during pacing from the LPVs during the RF delivery was significantly longer in the patients with AMF from the upper LPV than in those patients without (107±36ms vs. 146±40ms, p<0.01). CONCLUSION The LLR includes the preferential conduction properties between the CS and LPVs, and the observation of the serial changes during the RF delivery could provide us information about the LPVs arrhythmogenicity.

Effectiveness of Carvedilol on Premature Ventricular Complexes Originating from the Bilateral Papillary Muscles in the Left Ventricle

It has been reported that idiopathic focal ventricular arrhythmias can originate from the papillary muscles in the left ventricle (LV), but the clinical features remains unclear and the treatment has not been established. We report on a 75-year-old male patient presenting with a dilated cardiomyopathy and frequent ventricular premature complexes (VPCs). Ventricular arrhythmia was refractory to betaxolol (10 mg), mexiletine (300 mg) and Atenolol (25 mg). Three years after the onset of palpitations the patient evolved from NYHA functional class I (NYHAI) to class III, with a LVEF of 28%. VPCs comprised 66% of the total number of QRS complexes during 24 h Holter monitoring (Holter). During electrophysiologic study LV geometry was reconstructed using a CARTO system and the activation maps for two types of frequent VPCs revealed centrifugal activation patterns from two separate sites at the anterior and posterior papillary muscle. Radiofrequency catheter ablation was performed, but could not eliminate VPCs. Then, Carvedilol, at a dose of 20 mg/day, was administrated and suppressed VPCs very effectively. One year later, the patient was in NYHAI with LV reverse remodeling and LVEF of 51%. Holter showed only 727 VPCs. In conclusion, frequent VPCs arising from the bilateral left papillary muscle induced significant LV dysfunction and it was supressed effectively with Carvedilol, following LV reverse remodeling.