Technical and electrophysiological aspects of multisite cardiac stimulation through the access of the middle cardiac vein

Funding Acknowledgements Type of funding sources: None. Main funding source(s): Alfredo Aurélio Marinho Rosa and Alfredo Aurélio Marinho Rosa Filho Background Heart failure (HF) is a serious, progressive disease, caused by ventricular dysfunction, leading to a worsening in quality and a reduction in life expectancy. Cardiac resynchronization therapy through multisite stimulation has become an important tool in the treatment of advanced HF, however, due to anatomical variations and even the absence of appropriate veins for the insertion of the left ventricular electrode, the access of the middle cardiac vein can be an option for biventricular cardiac stimulation. Objective: To present the technique used to access the middle cardiac vein (MCV) for the implantation of the left ventricular electrode and the results of this multisite stimulation. Material and Method: Between March 2006 and May 2016, 388 patients (PT) underwent biventricular stimulation (BIV) at our service. 276 PT (71.1%), were associated with the cardioverter-defibrillator (ICD), 226 PT (58.2%) were male and their age ranged from 28 to 84 years with an average of 64 years. In this group, in 63 PT (16.2%) the left ventricular electrode was implanted through CMV. The technique initially consists of introducing a deflectable catheter for marking the coronary sinus (SC) via the femoral approach, then the SC approach is performed by puncturing the left subclavian vein, introducing an 8F sheath up to the proximal 1/3, where the VCM venogram is performed by introducing a 0.014 "guide wire and the 5 F bipolar or quadripolar electrode, then defining the best electrode position from the smallest stimulated QRS. Results: In this group of 63 PT, 52 PT (82.5%) responded to cardiac resynchronization therapy. The most frequent cardiopathies involved were ischemic (38%), chagasic (25%), hypertensive (12%) and others (25%). The thresholds varied from 3.5 to 0.5 V, impedance from 600 to 1200 ohms and sensitivity between 10 and 20 mV. There were no complications in the trans or post implant and in 5 PT (7.9%), there was phrenic stimulation. The procedure time varied from 50 to 180 minutes. Conclusion: Multisite stimulation through the access of the middle cardiac vein proved to be a possible alternative, easy to perform and with a high PT index responsive to cardiac resynchronization therapy.

Morphometric traits of selected heart veins of standard and mutational colour variants of American mink (Neovison vison)

The aim of the study was to estimate the values of metric traits of selected mink heart veins of standard and mutation colour variants. The study was conducted on 342 hearts of seven-month-old males and 405 hearts of seven-month-old females. Mink colour, resulting from mutation or from crossbreeding mutational colour variants with each other. Metric traits of the coronary sinus, great cardiac vein, middle cardiac vein, posterior vein, and small cardiac vein were determined by photographic recording of the sub-epicardial picture of these vessels after filling them with a water-dilutable dye for acrylic paints together with a 30% food gelatin solution. In addition, the number of the veins forming the great cardiac vein and that of the posterior veins of the left ventricle were determined. Based on the measurement of the width and length of the mink hearts, the heart shape was determined. Differences were found between the traits of the mink heart vessels of standard and mutational colour variants, but they did not allow to formulate clearly the thesis about the effect of mutations on these traits.

Biventricular implantable cardioverter-defibrillator device placement in patients with hostile tricuspid valve anatomy: two case reports and review of the literature

Aims Right ventricular (RV) lead placement can be contraindicated in patients after tricuspid valve (TV) surgery. Placement of the implantable cardiac-defibrillator (ICD) lead in the middle cardiac vein (MCV) can be a viable option in these patients who have an indication for biventricular (BiV) ICD. We aim to describe the case of two patients with MCV lead placement and provide a comprehensive review of patients with complex TV pathology and indications for RV lead placement. Methods and results We describe the cases of two patients with TV pathology unsuitable for the standard transvenous or surgical RV lead placement and undergoing BiV ICD implantation. Their characteristics, procedure, and outcomes are summarized. The BiV ICD was successfully placed with the RV lead positioned in the MCV in both patients. The procedures had no complications and were well-tolerated. On follow-up, both patients had appropriate tachytherapy with no readmissions for heart failure or worsening of cardiac function. Conclusion Right ventricular lead placement of BiV ICD in the MCV can be an excellent alternative in patients with significant TV pathology and poor surgical candidacy.