Three-dimensional reconstruction of the coronary sinus with rotational angiography.

BACKGROUND: High-speed rotational coronary venous (CV) angiography (RCVA) permits dynamic, multi-angle visualization of the CV anatomy. METHODS AND RESULTS: RCVA uses a rapid isocentric rotation over a 108 degrees arc, right anterior oblique (RAO) 54 degrees to left anterior oblique (LAO) 54 degrees, in 4 s. Three-dimensional models of the venous tree were reconstructed, and the rotational images were analyzed using a full range of gantry angles, providing the operator with considerably more information about the CV anatomy than standard coronary sinus angiography images (SCVA). CONCLUSIONS: The SCVA view, which optimally displayed the appropriate coronary sinus branch for left ventricular lead implantation, was often different from the conventional RAO and LAO views.

Full-motion two- and three-dimensional pulmonary vein imaging by intracardiac echocardiography after pulmonary vein isolation.

BACKGROUND: The pulmonary veins (PVs) are topographically complex and motile, so angiographic visualization of the PVs anatomy is limited. An imaging technique that accurately portrays the pulmonary vein (PV) anatomy would be valuable during and after catheter ablation procedures. PURPOSE: We investigated whether three-dimensional (3D) intracardiac echocardiography (ICE) can visualize radiofrequency (RF)-induced tissue changes after PV isolation. METHODS: We performed 3D ICE studies with a 9F, 9-MHz ICE catheter after segmental or extended PV isolation. The ICE catheter was placed 3-4 cm inside the PV ostium and mounted onto a pullback device. Sequential two-dimensional (2D) images of the full length of the vein were obtained in 0.3 mm steps with cardiac and respiratory cycle gating. Each image was fed into a computer, and the aggregate data set was reconstructed into a 3D, full-motion image. RF lesion location and lesion size were studied on 67 pullback images from 29 patients. RESULTS: The 2D and 3D reconstruction was possible for 27 left superior PVs, 13 left inferior PVs, 26 right superior PVs, and one right inferior PV. The ablation site was identified 3-7 mm inside the PV ostium, and a 1/2 - 4/5 circumferential area was ablated with no clinically relevant stenosis. No significant differences were found on the ablated area or ablation site between segmental and extensive PV isolation. CONCLUSION: The 2D and 3D ICE of the PVs provides detailed anatomical information of the proximal PVs, and RF-induced tissue changes in the PV wall can be visualized by ICE.

Anatomic and electrophysiologic differences between chronic and paroxysmal atrial flutter: intracardiac echocardiographic analysis.

BACKGROUND: It remains unknown why atrial flutter (AFL) occurs as either a chronic or paroxysmal arrhythmia. PURPOSE: The aim of the study was to compare intracardiac echocardiographic (ICE) images of the crista terminalis (CT) and transverse conduction properties of the CT between chronic and paroxysmal forms of common AFL. METHODS: Chronic AFL (n = 7) was defined as non-self-terminating AFL lasting >1 month, and paroxysmal AFL (n = 8) was defined as an intermittent arrhythmia with symptomatic episodes of 24 hours maximum duration. ICE images of the right atrium were recorded with a 9 F 9-MHz intracardiac ultrasound catheter during pullback at 0.5-mm intervals from the superior vena cava to the inferior vena cava triggered by electrocardiogram and respiration. The two-dimensional image of the right atrium was reconstructed into a three-dimensional (3-D) image. RESULTS: Three-dimensional images from patients with chronic AFL showed the CT to be thick and continuous, and conduction across the CT was blocked at a pacing rate just above sinus rhythm in all seven patients. In contrast, 3D images from paroxysmal AFL showed the CT to be thin and discontinuous, and conduction across the CT during midseptal pacing was observed in five of the eight patients. CONCLUSION: The nature of AFL is determined, at least in part, by anatomic and electrophysiologic characteristics of the CT.

Radiofrequency catheter ablation of ventricular tachycardia originating in the left posterior and left anterior fascicles in a patient with prior myocardial infarction.

A 61-year-old man with prior anteroseptal myocardial infarction (ejection fraction: 40%) presented with recurrent episodes of palpitations. Twelve-lead ECG during palpitations showed an incessant ventricular tachycardia (VT1) with right bundle branch block (RBBB) morphology and inferior axis. Electrophysiologic study revealed that the clinical VT originated from the anterolateral left ventricle. A Purkinje potential preceded onset of the QRS complex by 34 ms. Radiofrequency ablation guided by the Purkinje potential terminated the VT1. Another ventricular tachycardia (VT2) showing RBBB morphology with superior axis and originating from the posteroseptal left ventricle, was induced by programmed ventricular stimulation. A Purkinje potential preceded onset of the local ventricular potential by 120-130 ms in this VT. Radiofrequency ablation guided by the Purkinje potential terminated the VT2.

Electrocardiographic and electrophysiologic characteristics in patients with Brugada type electrocardiogram and inducible ventricular fibrillation: single center experience.

BACKGROUND: The study examined the electrocardiographic and electrophysiologic characteristics in relation to programmed ventricular stimulation (PVS)-induced ventricular fibrillation (VF) in patients with Brugada syndrome. METHODS AND RESULTS: Thirty-four patients with a Brugada-type electrocardiogram (ECG) were enrolled. Twelve patients had a type 1 ECG, 12 had a type 2 ECG, and 10 had a type 3 ECG. PVS was performed with up to 2 ventricular premature beats from the right ventricular apex and outflow tract at 2 basic cycle lengths (600 and 400 ms). VF was induced in 17 of 23 (74%) asymptomatic patients and 10 of 11 (91%) symptomatic patients (p<0.05). The 27 patients in whom VF was induced by PVS and 7 patients without inducible VF were followed up for 47.1+/-33.7 months. One sudden death occurred during the follow-up period among asymptomatic patients with inducible VF, and no sudden death occurred among patients without inducible VF. CONCLUSIONS: In conclusion, inducibility of ventricular arrhythmia is high in patients with Brugada syndrome, but it does not correlate with clinical presentation. Few arrhythmic events occur during follow up. However, the present study data suggest that electrophysiologic study-induced VF does not predict arrhythmic events during follow up.

Beneficial effect of beraprost sodium plus telmisartan in the prevention of arterial stiffness development in elderly patients with hypertension and cerebral infarction.

Beraprost sodium (BPS, an analogue of prostacyclin) and telmisartan (TS, an angiotensin receptor blocker) have been reported to have a preventive effect on arterial stiffness in patients with cardiovascular diseases. The purpose of this study was to estimate the effects of a combined therapy using BPS and TS on arterial pulse wave velocity (PWV) values in elderly patients with hypertension and cerebral infarction. Over a 3-month period, 80 subjects with hypertension and histories of cerebral infarction received BPS only (120 microg/day p.o.), TS only (40 mg/day p.o.), both BPS and TS, or no medication at all (control). Arterial PWV and ankle brachial indices (ABI) were determined prior to and after 3 months of drug administration. During the follow-up, there were no significant changes in any of the parameters monitored with the exception of a significant decrease in systolic blood pressure in the BPS only, TS only, and BPS plus TS groups when compared to controls. The difference values for PWV in the control group, BPS only group, TS only group, and BPS plus TS group were +232.5, -114.6, -151.5, and -248.1 cm/s, respectively. The reduction values were significantly more pronounced in the BPS plus TS group than in the BPS only (P=0.037) and the TS only (P=0.022) groups. When BPS is combined with TS, an overall additive effect is seen in the improvement of PWV in Japanese patients with hypertension and cerebral infarction. This combination therapy is more beneficial than the corresponding monotherapies.

Electrophysiologic and anatomical characteristics of the right atrial posterior wall in patients with and without atrial flutter: analysis by intracardiac echocardiography.

BACKGROUND: The posterior right atrial transverse conduction capability during typical atrial flutter (AFL) is well known, but its relationship to the anatomical characteristics remains controversial. METHODS AND RESULTS: Thirty-four AFL and 16 controls underwent intracardiac echocardiography after placement of a 20-polar catheter at the posterior block site during AFL or pacing. In 31 patients, the effective refractory period (ERP) at the block site was determined as the longest coupling interval that resulted in double potentials during extrastimuli from the mid-septal (SW) and free (FW) walls. The block site was located 3.0-29.0 mm posterior to the crista terminalis (CT) in each AFL and control patient. The CT area indexed to the body surface area was larger in AFL patients than in control patients (16.4+/-6.5 mm(2)/m(2) vs 11.3+/-6.4 mm(2)/m(2), p=0.01), and was positively correlated to age (r=0.34, p=0.02). The ERP was longer in the AFL patients than in controls (SW: median value 600 [270-725] ms vs 220 [200-253] ms; FW: 280 [230-675] ms vs 215 [188-260] ms, p<0.05 for each). CONCLUSIONS: A functional block line was located on the septal side of the CT in all patients. A limited conduction capability and age-related CT enlargement might have important implications for the pathogenesis in AFL.

Usefulness of the polarity in high-density wide range-filtered bipolar mapping to detect isthmus block during radiofrequency ablation of typical atrial flutter.

BACKGROUND: The atrial activation sequence around the tricuspid annulus (TA) cannot always be used to establish whether complete block has been achieved across the cavotricuspid isthmus (CTI) during radiofrequency ablation (RFCA) for typical counterclockwise atrial flutter (CCW-AFL). AIM: We examined whether a change in the polarity of the atrial high-density wide range-filtered bipolar electrograms recorded near the ablation line is an accurate indicator of complete CTI block. METHODS: Nineteen patients with CCW-AFL underwent RFCA. Electrograms were recorded around the TA with duodecapolar conventional (2mm x 8mm x 2mm spacing) and high-density (2-mm spacing) Halo catheters. The bipolar electrograms on the high-density Halo catheter recorded from a series of adjacent electrode pairs positioned just lateral to the ablation line were filtered at a bandpass setting of 0.05-500 Hz. The activation sequence on the conventional Halo catheter during coronary sinus pacing (CSp) and inferolateral TA pacing, and the bipolar electrograms on the high-density Halo catheter during CSp were determined before and after RFCA. The final complete CTI block was verified by the presence of widely split double electrograms > or =100 msec along the ablation line. RESULTS: The final complete CTI block was achieved in all the 19 patients. Before RFCA, the polarity of bipolar electrograms was predominantly negative during CCW-AFL and positive during CSp. In 18 of the 19 patients, the bipolar electrograms exhibited the CCW activation and a negative polarity during CSp only after complete CTI block. In one of those 18 patients, additional applications of RFCA changed the polarity of bipolar electrograms positive to negative although the conventional Halo electrogram activation sequence suggested complete CTI block during CSp. In seven patients, who had transverse conduction across the crista terminalis during CSp, the conventional Halo electrogram activation sequence suggested an incomplete CTI block. However, in six of those seven patients, the CCW activation had a predominantly negative polarity of the bipolar electrograms. In one of those seven patients, complete CTI block was unable to be detected even using the high-density Halo catheter. CONCLUSIONS: These data demonstrate that the high-density wide range-filtered mapping can identify the CTI block in undetectable cases of complete CTI block or incomplete CTI block by the conventional method. The polarity of the bipolar electrograms recorded just lateral to the ablation line during CSp after RFCA of AFL may be used as a simple and an accurate indicator of complete CTI block.

Anatomical characteristics of the cavotricuspid isthmus in patients with and without typical atrial flutter: Analysis with two- and three-dimensional intracardiac echocardiography.

INTRODUCTION: The cavotricuspid isthmus (CTI) is crucial in the ablation of typical atrial flutter (AFL), and consequently the CTI anatomy and/or its relation to resistant ablation cases have been widely described in human angiographic studies. Intracardiac echocardiography (ICE) has been shown to be a useful tool for determining detailed anatomical information. Thus, this technology may also allow the visualization of the anatomical characteristics of the CTI, providing an opportunity to further understand the anatomy. AIM: We conducted a study to compare the anatomy of the CTI between the patients with and without AFL and to characterize the anatomy of the CTI in the patients with AFL resistant to ablation. MATERIALS AND METHODS: Twelve patients with typical AFL and 20 without AFL were enrolled in the study. Two-dimensional (2D) intracardiac echocardiography (ICE) was performed. The recordings were obtained with a 9F, 9-MHz ICE catheter from the right ventricular outflow tract to the inferior vena cava by pulling the catheter back 0.3 mm at a time under guidance with echocardiographic imaging in a respiration-gated manner. Three-dimensional (3D) reconstruction of the images of the CTI were made with a 3D reconstruction system. After the acquisition of the ICE, the CTI ablation was performed in the patients with AFL. RESULTS: The 2D and 3D images provided clear visualization of the tricuspid valve, coronary sinus ostium, fossa ovalis and Eustachian valve/ridge (EVR). The CTI was significantly longer in the patients with AFL than in those without AFL (median length 24.6 mm (range 17.0-39.1 mm) versus median length 20.6 mm (range 12.5-28.0 mm), respectively, P < 0.05). However, a deep recess due to a prominent EVR was observed in 9 of 12 (75%) patients with AFL and in 12 of 20 (60%) patients without AFL (N.S.). A deep recess and the relatively long CTI were related to aging in all the study patients, and that relationship was similar in a limited number of patients without AFL. In five patients with AFL resistant to ablation, a deep recess and prominent EVR were observed. CONCLUSIONS: The 2D and 3D ICE were useful for visualizing the complex anatomy of the CTI and identifying the anatomical characteristics of the CTIs refractory to ablation therapy. The anatomical changes observed in the CTI region may simply be the result of aging and may partially be involved in the development of AFL.

Complete AV block developing in a patient with manifest ventricular preexcitation.

This case report describes a 37-year-old man with manifest atriofascicular and fasciculoventricular connections who developed complete atrioventricular block. After resumption of 1:1 atrioventricular conduction, an electrophysiological study was conducted. During sinus rhythm, manifest ventricular preexcitation was observed and the AH and HV intervals were 80 msec and 50 msec, respectively. No change in AH interval during constant atrial pacing was observed by bolus injection of 20 mg of adenosine triphosphate. No changes in the morphology of the delta wave or HV interval were observed by changing the atrial pacing site. This patient developed HV block by atrial extrastimulus (S1S1: 600 msec, S1S2

Relationship between anatomic location of the crista terminalis and double potentials recorded during atrial flutter: intracardiac echocardiographic analysis.

INTRODUCTION: The activation sequence in typical atrial flutter (AFL) around the tricuspid annulus is well described. However, activation of the remainder of the right atrium (RA) is not well defined. Previous studies have shown a linear block at the crista terminalis (CT) during AFL. The aim of this study was to evaluate the relationship between the location of the CT and the line of block by intracardiac echocardiography (ICE). METHODS AND RESULTS: Twenty-one patients with typical AFL were included in the study. The ICE imaging catheter (9-French with 9-MHz ultrasound transducer) was advanced to the RA. Under ICE guidance, a 20-pole roving catheter was used to map double potentials (DPs) during AFL, and three-dimensional images of the RA were reconstructed. During counterclockwise (CCW), clockwise (CW) AFL, or both, a line of conduction block manifested by DPs was identified at a septal site adjacent to the CT in 12 patients and in the posteroseptal RA in 9 patients. CONCLUSION: The functional line of block in CCW and CW AFL is localized not at the CT but at the septal edge of the CT or in the posteroseptal RA.