Kenji Enta

Applicability of 3-Dimensional Quantitative Coronary Angiography-Derived Computed Fractional Flow Reserve for Intermediate Coronary Stenosis

BACKGROUND Quantitative flow ratio (QFR) is a newly developed image-based index for estimating fractional flow reserve (FFR).Methods and Results:We analyzed 151 coronary arteries with intermediate stenosis in 142 patients undergoing wire-based FFR measurement using dedicated software. Predefined contrast flow QFR, which was derived from 3-dimensional quantitative coronary angiography (3-D QCA) withThrombolysis in Myocardial Infarction (TIMI) frame counts, was compared with FFR as a reference. QFR had good correlation (r=0.80, P<0.0001) and agreement (mean difference: 0.01±0.05) with FFR. After applying the FFR cut-off ≤0.8, the overall accuracy rate of QFR ≤0.8 was 88.0%. On receiver operating characteristics analysis, the area under the curve was 0.93 for QFR. In contrast, 3-D QCA-derived anatomical indices had insufficient correlation with FFR and diagnostic performance compared with QFR. CONCLUSIONS QFR had good correlation and agreement with FFR and high diagnostic performance in the evaluation of intermediate coronary stenosis, suggesting that QFR may be an alternative tool for estimating myocardial ischemia.

Primary Multiple Cardiac Myxomas in a Patient without the Carney Complex.

Cardiac tumors are rare, and multiple myxomas are even rarer. The latter phenomenon is mostly associated with the Carney complex, a dominantly inherited disease characterized by multiple primary cardiac myxomas, endocrinopathy, and spotty pigmentation of the skin. We report the rare case of a patient who did not have the Carney complex but had multiple primary cardiac tumors. A 78-year-old woman with a past history of breast cancer was referred to our hospital for further examination of multiple cardiac tumors. Echocardiography showed 4 tumors in the left atrium and left ventricle. We could not diagnose them preoperatively and decided to resect them surgically because they were mobile and could have caused embolism and obstruction. The postoperative pathological findings of all 4 tumors were myxomas, although the patient did not meet the diagnostic criteria of the Carney complex. Therefore, a rare case of multiple primary cardiac myxomas was diagnosed.

Occurrence of Potentially Lethal Arrhythmia due to Sudden Exposure of an Overt Accessory Pathway 8 Years After Catheter Ablation of a Concealed Accessory Pathway

Although the efficacy of catheter ablation of the accessory pathway (AP) has been established, there are subgroups of APs with an intermittent conduction property, which is sometimes difficult to diagnose accurately. A 57-year-old man with a history of catheter ablation was referred to our clinic due to frequent faintness. He had undergone concealed AP ablation 8 years previously and bilateral circumferential pulmonary vein isolation (CPVI) 6 years previously. During regular electrocardiogram monitoring, it was suggested that irregular wide QRS tachycardia, which was considered to be atrial fibrillation with antegrade AP conduction, was the cause of the present symptoms. In the present electrophysiological study, we noticed a residual antegrade AP in the left lateral wall that was not observed during the previous session. We achieved abolition of overt accessory conduction, bilateral CPVI, and superior vena cava isolation with several radiofrequency applications without any recurrence. We also confirmed the absence of dormant conduction in the AP and the left atrium-PV connection with 20 mg adenosine triphosphate. This case demonstrated the possibility of sudden exposure of overt AP conduction late after catheter ablation of the concealed AP and the importance of confirming the absence of dormant conduction by means of adenosine triphosphate, which has the potential benefit of revealing latent AP conduction.

Cause of the “power-on reset” phenomenon other than electric magnetic interference in a patient with a pacemaker

A 67-year old male with a dual-chamber pacemaker visited for a regular check-up. An unfamiliar message emerged on the display just after placing the programmer wand. We could recognize that the pacemaker had already been in the safe back-up mode of DDI, and the programmer prompted a re-initialization request. We are so surprised because there was no indication of device malfunction the day before in daily monitoring and a 12-lead electrocardiogram revealed normally working in the DDD mode just before checking the device. The pacemaker was immediately re-programmed to the former setting. This phenomenon has not recurred for 12 months.

Successful elimination of premature ventricular contractions by ablation of origin and preferential pathway

However, the common strategy for eliminating premature ventricular contractions (PVCs) is to explore the exit site and ablate, which may be difficult in some cases. The origin and the preferential pathway, an insulated pathway connected to the exit, may also become targets for eliminating PVCs.

Interesting electrophysiological findings in a patient with coexistence of atrial tachycardia originating from coronary sinus and slow-fast atrioventricular nodal reentrant tachycardia

Slow-fast atrioventricular nodal tachycardia (AVNRT) has various electrophysiological aspects due to atrioventricular (AV) nodal physiology. In addition, concomitantly another form of arrhythmia with AVNRT, especially atrial tachycardia (AT), was an infrequent arrhythmia. A 38-year-old female with narrow QRS tachycardia underwent electrophysiological study due to frequent faintness. The electrophysiological study disclosed the coexistence of AT originating from coronary sinus (CS) with slow-fast AVNRT. We easily diagnosed AT originating from CS and terminated with several radiofrequency ablations (RFA) around CS. The diagnosis of slow-fast AVNRT, however, was somewhat difficult due to the following findings: (1) small amount of adenosine triphosphate (ATP) could terminate slow-fast AVNRT reproducibly; (2) we could provoke slow-fast AVNRT only by RV pacing with isoproterenol infusion. With other electrophysiological findings, we diagnosed slow-fast AVNRT. Radiofrequency energy was delivered initially in the posteroseptal region, followed by inside CS, and finally in the middle septal region, which completed the slow pathway ablation. After the procedure, we could never provoke these arrhythmias. <Learning objective: Coexistence of focal AT originating from CS with slow-fast AVNRT is a rare phenomenon. Furthermore, slow-fast AVNRT could show unusual characteristic as following: (1) small amount of ATP terminates slow-fast AVNRT; (2) atrial pacing never provoked slow-fast AVNRT with isoproterenol infusion whereas ventricular pacing did, which depends on the physiological characteristic of the dual AV nodal pathway. Accordingly, we should precisely assess the obtained electrophysiological findings.>.

Focal right atrial tachycardia with three foci in a patient with polymyositis

Cardiac involvement secondary to polymyositis is not infrequent. In addition, it sometimes presents various forms of arrhythmia, including atrial tachycardia (AT). A 72-year-old female who had 5-years history of polymyositis was referred to our clinic with symptomatic supraventricular tachycardia with 2:1 atrioventricular conduction. Electrophysiological study revealed a total of three focal AT in right atrium with the origin of the basal right atrial appendage (AT1), coronary sinus ostium (AT2), and low lateral right atrium (AT3), respectively. Endocardial bipolar voltage mapping showed low voltage area in the limited area, partially overlapping with the focus of AT3. We finally terminated AT2 targeting an early fractionated potential and AT3 at early activation site with a support of flexibly-bended deflectable sheath while accidentally eliminating AT3 with the bumping of a catheter. With the additional applications, we completely eliminated all AT. AT were never provoked by any inductions with isoproterenol infusion. <Learning objective: Polymyositis is a broad-spectrum inflammatory disease which could involve myocardium, sometimes leading to the arrhythmogenicity. We should recognize the possibility of arrhythmia occurrence with multiple foci in patients with polymyositis when performing catheter ablation even if there were no obvious structural and functional heart abnormality.>.

Successful angioplasty with intravascular ultrasound and optical frequency domain imaging guidance for tandem intramural hematoma caused by coronary artery spasm

A 39-year-old woman with no coronary risk factors was admitted due to repetitive morning chest pain. Coronary angiography revealed subtotal occlusion of the distal obtuse marginal branch that was not recanalized by intracoronary nitroglycerin administration. Intravascular ultrasound and optical frequency domain imaging showed tandem intramural hematomas in the culprit vessel. We performed cutting balloon angioplasty successfully with dual intracoronary imaging modality guidance. The 4-month follow-up angiography revealed favorable vascular healing and the provocation test induced multiple spasms, including in the culprit vessel, by intracoronary acetylcholine administration. <Learning objective: Coronary artery spasm could be the cause of tandem intramural hematomas with clinical presentation of acute coronary syndrome. Angioplasty with dual imaging modality guidance is a useful option for diagnosing and treating for intramural hematoma.>.

A simple method to ablate left-sided accessory pathways in a patient with coronary sinus ostial atresia and persistent left superior vena cava: A case report

Introduction Wolff-Parkinson-White (WPW) syndrome is characterized by a short PR interval, wide QRS complex, and paroxysmal supraventricular tachycardia. An accessory atrioventricular connection is known to be the underlying mechanism of this syndrome. Accessory pathways (APs) are mainly located along the tricuspid or mitral annulus, accounting for 10%– 20% and 50%–60% of cases, respectively. Multielectrode recordings from a coronary sinus (CS) catheter facilitate the identification of the location of left free-wall APs; therefore, the usage of CS catheters is currently the standard for ablation of left free-wall APs. Coronary sinus atresia is a rare anomaly and is generally accompanied by venous drainage into (1) a persistent left superior vena cava (PLSVC), (2) the left atrium through an unroofed CS, or (3) the cardiac chambers through collateral venous pathways. This anomaly becomes a problem in procedures such as cardiac resynchronization therapy or catheter ablation of a left-sided AP, which require cannulation of the CS. Herein, we present a rare case of a 43-yearold woman with 2 left-sided APs accompanied by coronary sinus ostial atresia (CSOA) and a PLSVC.

A dancing stone in the pericardial cavity

An 80-year-old man visited to our department because of exertional dyspnoea. Cardiac computed tomography revealed multi-vessel coronary artery narrowing. Ultrasonography showed calcified aortic valve of 1.0 cm2 valve area. Cardiac catheterization revealed three-vessel coronary disease with a chronic total occlusion in the left …