A successful placement of the left ventricular lead for the cardiac resynchronization device using the orthodromic snare technique: clinical case

Background: The main aim of Cardiac Resynchronization Therapy (CRT) is a positive response of the patient, particularly, reduction of the symptoms and improvement of the heart contractility, that can be reached in 5070% of patients. The possibility of appropriate positioning the left ventricular (LV) lead is of great importance for the response to CRT. Certain instruments and technical approaches are used for the placement of the LV lead. Here, we describe the use of the orthodromic snare technique, which is quite rare in practice, but allows one to overcome some anatomical obstacles. Clinical case description: Patient A., suffering from the heart failure with a low ejection fraction and left bundle branch block, was admitted to the hospital for CRT implantation. Before the operation, all the necessary routine instrumental and laboratory diagnostics was performed. During the operation, venography of the cardiac veins revealed unsuitability of the lateral cardiac vein for the placement of the LV lead due to its very small diameter. The posterolateral vein was suitable for the LV lead implantation but still had some anatomical difficulties: an acute angle of inflow and local stenosis in the proximal segment. During the procedure, the following techniques were used without success: positioning the LV lead by a simple translational movement forward, a subselective catheter, introduction of several coronary guides in order to smooth out the acute angle of inflow. These circumstances warranted the use of the orthodromic snare technique for a successful LV lead placement. Conclusion: This clinical case illustrates the possibility of a safe and effective use of the orthodromic snare technique for LV lead implantation. Such anatomical difficulties as a small diameter, acute angle of inflow, local stenosis have also been illustrated and discussed.

Single-shot cryoablation of an epicardial inferoparaseptal accessory pathway: a case report

Background Catheter ablation (CA) of epicardial accessory pathways (APs) can be performed via the coronary sinus (CS) system. Variable CS anatomy with complications of former CA procedures inside the CS venous system may require using alternative CA approach and technology. Case summary We report the case of a 23-year-old man with Wolff–Parkinson–White syndrome and history of aborted sudden cardiac death (SCD) and unsuccessful previous AP radiofrequency ablation (RFA). CS venography during the redo procedure revealed an early CS trifurcation with cardiac veins stenosis, thus with difficulties in maintaining cardiac veins’ access and catheter manoeuvring inside CS venous system. The last office visit with electrocardiogram (ECG) performance was in 3 months after the CA. Neither delta wave on the ECG nor any complaints/adverse health effects was detected at that time. Discussion Successful CA of epicardial AP in patients with a high risk of SCD is essential. However, CS complex anatomy and changes after former RFA inside it may lead to CS venous system access limitations. Alternative CA approach and technology should be considered to ensure CS venous system cannulation and epicardial AP CA performance.

The coronary arteries and cardiac veins

This chapter describes the anatomy of the coronary arteries and cardiac veins. It covers the coronary ostia and left coronary artery, the right coronary artery, the cardiac venous system, and the coronary sinus and its tributaries.

P5685Abnormal anatomy of the coronary sinus in congenitally corrected transposition of the great arteries (double discordance): a pitfall for transvenous cardiac resynchronization therapy?

Background Congenitally corrected transposition of the great arteries (ccTGA) or double discordance is a rare congenital heart defect associating discordant atrioventricular and ventriculoarterial connections. Late prognosis depends on the progressive failure of the systemic right ventricle (RV). A possible cause for systemic RV dysfunction could be ventricular asynchrony. Cardiac resynchronization therapy (CRT) may thus be indicated in some cases. However, the cardiologists may experience some problems with the coronary sinus (CS) when implanting a 3-lead CRT transvenous system in these patients. Aim of the study To evaluate the anatomy of the CS and cardiac veins in specimens with ccTGA, in order to assess the feasibility of transvenous CRT. Material and methods Among the anatomic collection of the French Centre of Reference for complex CHD, 51 heart specimens had ccTGA with 2 ventricles. There were 33 post-natal and 18 fetal hearts. Hearts were reviewed with special attention paid to the course and drainage of the CS and cardiac veins. Segmental anatomy, location of the ventricular septal defect (VSD), status of the pulmonary outflow tract and anomalies of the atrioventricular valves were reviewed. Results Segmental anatomy was {S,L,L} in 46/51 hearts, {S,L,D} in 2 and {I,D,D} in 3. There was a VSD in 40 (outlet in 25, inlet in 11, both in 2, muscular in 2), pulmonary atresia in 13, subpulmonary stenosis in 6, abnormal tricuspid valve in 20/48 including Ebstein anomaly in 6, straddling in 9 (3 had replacement). The CS was always located behind the morphologically left atrium (LA). However, its anatomy was normal, with normal drainage into the morphologically right atrium, in only 25/51 (49% of cases). The CS was of reduced length with normal orifice in 17. Orifice was atretic with normal size CS in 2, and CS was completely absent in 6 with direct drainage of coronary veins into the LA. At least 1 available vein was found in all cases with patent CS orifice. Conclusion CS in ccTGA is always located behind the morphologically LA. However, its anatomy is abnormal in half of cases. The most frequent anomalies are reduced length (33%) and absent CS or atretic orifice (15.5%). The anatomy of CS should therefore be assessed by imaging techniques (multislice CT imaging or CS venography) before considering transvenous CRT in these patients.

Moderate hypothermia and responses to calcium channel blockers – Role of the nitric oxide

Moderate hypothermia (25–31 °C) may have a significant influence on vascular tone. At present, very little is known about the role of endothelial nitric oxide on the hypothermia-induced responses. In this study, we investigated the effect of hypothermia (to 28 °C) on the vasodilatation induced by verapamil, a phenylalkylamine calcium channel blocker (10−9–3 × 10−4 M) and dihydropyridines, amlodipine (10−9–3 × 10−4 M), and benidipine (10−9–10−3 M) on 5-hydroxytryptamine (5-HT or serotonin) precontracted calf cardiac veins. Furthermore, the role of nitric oxide in the hypothermia-induced responses was analyzed. Ring preparations of veins obtained from calf hearts were suspended in organ baths containing 15 ml of Krebs–Henseleit solution, maintained at 37 °C, and continuously gassed with 95% O2–5% CO2. After a resting period, verapamil, amlodipine, and benidipine were applied cumulatively on serotonin (10−6 M) precontracted calf cardiac vein rings and induced concentration-dependent relaxations. In another part of the study, the medium temperature was decreased to 28 °C after the preparations were contracted with 5-HT, then cumulative concentrations of verapamil, amlodipine, or benidipine were added. During hypothermia, the pIC50 value, but not the maximal response, to all blockers were significantly higher than at 37 °C. Hypothermia in the presence of NG-nitro-l-arginine methyl ester (L-NAME, 10−4 M) decreased the pIC50 and Emax values to verapamil, amlodipine, and benidipine. Only one blocker was tested in each preparation. These results suggest that nitric oxide may play a role in the hypothermia-induced changes in vasodilation caused by verapamil, amlodipine, and benidipine in calf cardiac vein, but further research is needed to explain the complete mechanism.