Yukiko Hayama

Unexpectedly High Prevalence of Acquired von Willebrand Syndrome in Patients with Severe Aortic Stenosis as Evaluated with a Novel Large Multimer Index

AIM Severe gastrointestinal bleeding sometimes occurs in patients with aortic stenosis (AS), known as Heydes syndrome. This syndrome is thought to be caused by acquired von Willebrand syndrome and is characterized by reduced large von Willebrand factor (vWF) multimers. However, the relationship between the severity of AS and loss of large vWF multimers is unclear. METHODS We examined 31 consecutive patients with severe AS. Quantitative evaluation for loss of large vWF multimers was performed using the conventional large vWF ratio and novel large vWF multimer index. This novel index was defined as the ratio of large multimers of patients to those of controls. RESULTS Loss of large vWF multimers, defined as the large vWF multimer index ＜80%, was detected in 21 patients (67.7%). The large vWF multimer ratio and the large vWF multimer index were inversely correlated with the peak aortic gradient (R = -0.58, p=0.0007, and R=-0.64, p＜0.0001, respectively). Anemia defined as hemoglobin ＜9.0 g/dl was observed in 12 patients (38.7%), who were regarded as Heydes syndrome. Aortic valve replacement was performed in 7 of these patients, resulting in the improvement of anemia in all patients from a hemoglobin concentration of 7.5±1.0 g/dl preoperatively to 12.4±1.3 g/dl postoperatively (p＜0.0001). CONCLUSIONS Acquired von Willebrand syndrome may be a differential diagnosis in patients with AS with anemia. The prevalence of AS-associated acquired von Willebrand syndrome is higher than anticipated.

Relationship between plasma dabigatran concentration and activated partial thromboplastin time in Japanese patients with non-valvular atrial fibrillation

Activated partial thromboplastin time (aPTT) is recommended for monitoring anticoagulant activity in dabigatran‐treated patients; however, there are limited data in Japanese patients. To clarify the relationship between plasma dabigatran concentration and aPTT, we analyzed plasma dabigatran concentration and aPTT at various time points following administration of oral dabigatran in a Japanese hospital.

Effect of radiofrequency catheter ablation of persistent atrial fibrillation on the left atrial function: Assessment by 320-row multislice computed tomography

BACKGROUND Atrial fibrillation (AF) increases the left atrial (LA) volume and deteriorates LA function. Whether successful radiofrequency catheter ablation (RFCA) of persistent AF can reverse this process has not been yet established. METHODS Patients with persistent AF undergoing RFCA were evaluated with pre- and post- (at 6-months of follow-up) procedural multislice computed tomography (MSCT). The LA functions were assessed through LA time-volume curves. RESULTS The study population consisted of 44 patients [age 64 (interquartile ranges: 58, 70) years old, 93% male]. Among those, 31 patients (70%) maintained sinus rhythm during the follow-up (no recurrence group; NR group). The remaining 13 patients were classified as the recurrence group (R group). A significant decrease in the minimal and maximal LA volumes was observed in both groups, although this was less pronounced in the R group. Only the NR group had an improvement in the LA expansion index [18% (13, 25) vs. 37% (23, 43), p<0.001], ejection fraction [15% (11, 20) vs. 27% (19, 30), p<0.001] and conduit function [17 ml/m(2) (13, 20) vs. 25 ml/m(2) (20, 34), p<0.001]. An improvement of LV function was also observed only in the NR group. CONCLUSIONS LA anatomical and functional reverse remodeling after RFCA of persistent AF was demonstrated by MSCT during follow-up, which was more pronounced in patients without AF recurrence.

A case of significantly increased mitral regurgitation early after atrial septal defect closure

We report a rare case in which mitral regurgitation (MR) was exacerbated to a severe level early after atrial septal defect (ASD) closure, even though the female patient had preoperatively mild MR and mild changes in mitral valve (MV) and sinus rhythm. The mechanism of increased MR was considered as poor coaptation and tethering of the MV due to the restricted motion of the posterior leaflet in addition to geometric changes of the left ventricle (LV) after ASD closure.

Detecting Cardiac Sarcoidosis with a Right Atrial Mass Using Transthoracic Echocardiography

An asymptomatic 40-year-old woman with a first-degree atrioventricular block presented a right atrial mass in transthoracic echocardiograms. Transesophageal echocardiograms showed abnormally thickened tissue on the interatrial septum, which extended around the aortic annulus. Multimodality examinations demonstrated lesions in the heart, lungs, liver, and spleen, suggesting sarcoidosis. She was diagnosed with cardiac sarcoidosis after we detected granulomas in a lung specimen. A right atrial mass shrunk following steroid therapy. We should therefore consider the possibility of cardiac sarcoidosis when we see wall thickening and a mass echo in the atrium. These signs may point to an early-phase lesion of cardiac sarcoidosis.

Successful radiofrequency catheter ablation of sinoatrial nodal reentrant tachycardia after a total cavo-pulmonary connection procedure with an extra-cardiac conduit

We report a tachyarrhythmia case of a 32-year-old female with a single ventricle and heterotaxy syndrome. She had surgery involving a total cavo-pulmonary connection procedure using an extra-cardiac conduit (EC) at the age of 17 years. A tachycardia was repetitively induced with single atrial extrastimuli. An activation map was created revealing a centrifugal propagation pattern from the high atrial wall adjacent to the EC. At that site, a structure resembling the crista terminalis was recognized with intracardiac echocardiography. Therefore, high output energy was required to eliminate the tachycardia. It was thought to be a sinoatrial nodal reentrant tachycardia. <Learning objective: Radiofrequency catheter ablation (RFCA) of supraventricular tachycardia (SVT) after a total cavo-pulmonary connection with an extra-cardiac conduit is challenging and the diagnosis of the SVT is difficult. However the electrophysiological features observed during the electrophysiological study using a three-dimensional mapping system, anatomical features observed with intracardiac echocardiography, and pharmacological features seen during a rapid intravenous injection of adenosine triphosphate can lead to an accurate diagnosis, and moreover lead to a successful RFCA.>.

Ablation of idiopathic ventricular fibrillation targeting short coupled ventricular premature contractions originating from a right ventricular papillary muscle

We describe a 38-year-old male who experienced several episodes of syncope after having ventricular fibrillation. The electrocardiographic monitoring after his hospitalization revealed repetitive polymorphic ventricular tachycardias. All polymorphic ventricular tachycardias were consistently initiated by a short-coupled monomorphic ventricular premature contraction (VPC). This VPC was suggested to originate from the inferoposterior region of the right ventricle (RV). Radiofrequency catheter ablation targeting the VPC was successfully performed, and the CARTO merge system (Biosense Webster Inc., Diamond Bar, CA, USA) revealed that the culprit region was the root of the posterior papillary muscle of the RV. A subsequent follow-up of 15 months has been uneventful. <Learning objective: This is a case report of idiopathic ventricular fibrillation (IVF) triggered by a ventricular premature contraction (VPC) from the posterior papillary muscle of the right ventricle. We can learn about the relationship between the anatomical structure and the possible mechanisms of the short-coupled variant of Torsade de Pointes.>.

Successful radiofrequency catheter ablation assisted by the CartoSound® system for outflow tract origin nonsustained ventricular tachycardia in a patient with a severely deformed thorax

We report the case of a 72‐year‐old man with a nonsustained ventricular tachycardia and a history of palpitations. He had a severely deformed thorax since childhood due to spinal caries. An integrated computed tomography image of the outflow tract region from the CartoSound® system revealed the detailed anatomical information around the origin of the tachycardia and that the left anterior descending coronary artery was very close (<10 mm) to the target site. We carefully ablated that site with a 3.5‐mm cooled‐tip catheter while confirming it in the sound view, and succeeded without any complications.