Obsessive Compulsive Disorder in a Patient with Twiddler's Syndrome

Twiddler's or twist syndrome is the twisting of pulse generators around themselves. It may result from mechanical manipulation that can induce the malfunction of the device. In this case, twiddler's syndrome resulted from compulsive checking of the device. The implantable cardioverter‐defibrillator (ICD) triggered the development of an obsessive compulsive disorder (OCD). Two invasive procedures were required to replace the ICD. Psychiatric intervention prevented the recurrence of twiddler's syndrome in this patient for more than 2 years. We believe that preimplant psychiatric assessment should be the rule.     

Mapping and Isolation of the Pulmonary Veins Using the PVAC Catheter

Objectives: We aimed to investigate the feasibility, efficacy, and safety of the pulmonary vein ablation catheter (PVAC) catheter (a novel multielectrode catheter using duty‐cycled bipolar and unipolar radiofrequency energy, Medtronic, Minneapolis, MN, USA) to completely isolate the pulmonary veins (PVs). Methods: Twenty‐seven patients (60 ± 8 years) with paroxysmal atrial fibrillation (AF) underwent PV isolation with the PVAC catheter. PVAC was used for both mapping and isolation of the PVs (PVAC‐guided ablation). After PVAC ablation, presence/absence of PV potentials (PVP) was verified using a conventional circular mapping catheter. In case of residual PVP on the circular catheter, PVAC ablation was continued. Results: After PVAC‐guided ablation 99 of 106 PVs (93%) and 21 of 27 patients (78%) were proven to be isolated. Failure to isolate was due to a mapping failure in four right‐sided PVs and a true ablation failure in three right‐sided PVs. After continued PVAC ablation, 103 of 106 PVs (97%) and 25 of 27 patients (93%) were shown to be isolated. The total procedural time from femoral vein access to complete catheter withdrawal was 176 ± 25 minutes. The actual dwelling‐time of the PVAC within the left atrium was 102 ± 37 minutes. Esophageal T° rise to >38.5° occurred in nine of 19 monitored patients (47%). Conclusions: (1) PVAC‐guided ablation (i.e., mapping and ablation with a single catheter) results in isolation of all PVs in 73% of the patients. (2) An additional circular mapping catheter is required to increase complete isolation rate to 93% of the patients. (3) Given the esophageal T° rise in almost 50% of patients, safety precautions are needed. (PACE 2010; 33:168–178)     

Myocardial Temperature Response During Radiofrequency Catheter Ablation

During radiofrequency catheter ablation, steady-state electrode-tissue interface temperatures are reached within 5 seconds. Within the myocardium, however, a much slower temperature rise has been observed in vitro with stabilization after approximately 2 minutes. This discrepancy suggests that tissue temperature rise time depends on distance from the ablation electrode and, thus, that temperature rise measured at the electrode-tissue interface does not correspond with temperature rise within the myocardium. In five beagles, closed-chest radiofrequency catheter ablation was performed in the vicinity of intramural thermocouples. Sequences of 60 seconds, 10- and 25-watt pulses were delivered in the unipolar mode via the 4-mm distal electrode of a 7 French steerable catheter. At all distances > 3 mm from the ablation electrode, the rate of myocardial temperature rise was low: relative rise after 5, 10, 20, and 30 seconds was 22%, 32%, 48%, and 63% of that achieved at 60 seconds, and even then steady-state temperatures had not yet been reached. Temperature rise was faster at sites closer to the ablation electrode. There was no difference in rate of rise between first and second pulses at the same site. A 6% higher myocardial temperature was reached with a second identical pulse at the same site. Tissue temperatures achieved with 25 watts were 2.4 times higher than with a preceding 10-watt pulse at the same ablation site.     

Angiographic Anatomy of the Coronary Sinus and Its Tributaries

Permanent left ventricular pacing has been shown to imporve the hemodynamic and clinical status of patients with severe heart failure. To pace the left ventricle, the electrode is implanted in tributaries of the coronary sinus (CS). However, the anatomy of cardiac veins with this purpose in mind has not been described in detail. Methods: One hundred consecutive patients admitted for coronary angiography had a simultaneous coronary venography performed after the injection of 8 to 10 mL of contrast material into the left coronary artery. Cardiac veins were analyzed in antero-posterior, left anterior oblique 60±, and right anterior oblique 30± views by three different observers. The number, dimension, angulation, and position of the coronary sinus and of its tributaries were studied. Results: Two veins are consistently present: the middle cardiac vein (mean diameter 2.62 ± 1.26 mm) and the great cardiac vein (mean diameter 3.55 ± 1.24 mm). The left posterior vein(s) (LPV) (mean diameter 2.25 ± 1.2 mm) is (are) variable in number (ranging from 0 to 3), size, and angulation. The absence of LPV limits the ability to pace the left ventricle endovenously. The diameter of the vein (< 2 mm) and its angulation may also complicate the insertion of the lead. Conclusion: Angiographic analysis of dimensions, tortuosity, number, and angulation of venous tributaries of the CS seems to allow the insertion of commercially available pacing leads in approximately 85% of cases. An increase in this percentage hinges on the development of new, dedicated leads.     

Surface Profile of the Internal Elastic Lamina May Modulate Thrombosis Following Intracoronary Radiation in Balloon-Injured Porcine Arteries

Background: Intracoronary radiation (IR) can prevent neointima formation (NF) by reducing smooth muscle cell (SMC) proliferation after balloon angioplasty, but is complicated by subacute and late thrombosis. Rupture or abnormalities of the internal elastic lamina (IEL) structure and subsequent exposure of blood to the injured arterial wall can induce thrombosis and inflammation. The purpose of this study was to evaluate the effect of IR on the media and IEL after balloon overstretch injury in porcine coronary arteries. Methods: Seventeen juvenile swine (25 coronary arteries) were injured by overstretch balloon and subsequently given IR at doses of 0 or 18 Gy ⁹⁰Y prescribed to 1.2 mm from vessel wall inner surface. Two weeks following treatment, tissue sections were perfusion fixed and stained by hematoxylin-eosin or by Verhoeff-von Giesson. Smooth muscle cell α-actin was detected immunocytochemically and quantified by digital image analysis using arbitrary density units. Histomorphometry was carried out to assess intimal area (IA) and IA corrected for medial fracture length (IA/FL). The roughness index (RI) of the IEL was calculated from the surface profile length and the straight-line length. Results: NF was markedly smaller after IR as compared to control treatment. Mural thrombi were increased significantly in irradiated versus control arteries (11/14 [78%] vs 1/11 [9%]; P < 0.001). A significant decrease in SMC density was observed in the irradiated group (128 ± 13 vs 74 ± 10; P < 0.001) despite a lack of difference in medial area. The surface of the IEL was more irregular in irradiated arteries, particularly at the medial breaks (RI =20.1 ± 3.1 vs 8.7 ± 1.2; P < 0.001). When mural thrombi were present, thrombus area correlated with RI (α= 0.76; P < 0.01). Furthermore, in the irradiated group RI correlated positively with SMC density (α=0.64; P < 0.01). Conclusion: Medial structure and RI may be useful parameters by which to assess arterial healing following IR. These findings may influence the design of future IR studies aimed at reducing thrombosis and enhancing arterial healing.     

Perspective on Bifurcation PCI

Coronary bifurcation lesion is a complex lesion with suboptimal angiographic and clinical results. There has been no satisfactory classification of the lesion that can guide selection of strategies and predict short- and long-term outcomes. The difference between left main (LM) bifurcation lesions and non-LM bifurcation is striking. So many stenting strategies have been proposed and tried in trials. They include the V, T, Y, one-stent, two-stent, crush, mini-crush, DK, and SKS techniques. However, because these techniques are time and labor intensive, dedicated bifurcated stents have been invented and trialed in humans. This review presents a historical perspective of interventions in bifurcated lesions, with the strengths and weaknesses of the major strategies and of the new dedicated stents.