Single site pacing through the anterior interventricular vein in a patient with a mechanic tricuspid valve

Transvenous endocardial pacing through classical implantation of a pace/sensing lead in the right ventricle is strictly contraindicated in patients with a mechanical tricuspid valve. Usually permanent pacing is achieved by an epimyocardial surgical approach. We hereby describe the implantation of a single site left ventricle pacing lead in the anterior interventricular vein in a 60 year-old woman with symptomatic bradycardia, permanent atrial fibrillation, and mechanical tricuspid valve. The described use of left ventricle pacing through a coronary vein lead, in a patient with favorable venous anatomy, provided (through a minimal invasive approach) effective with a low and stable threshold.     

Visualisation of coronary venous anatomy by computed tomography angiography prior to cardiac resynchronisation therapy implantation

Background

The purpose of this study was to illustrate the additive value of computed tomography angiography (CTA) for visualisation of the coronary venous anatomy prior to cardiac resynchronisation therapy (CRT) implantation.

Methods

Eighteen patients planned for CRT implantation were prospectively included. A specific CTA protocol designed for visualisation of the coronary veins was carried out on a third-generation dual-source CT platform. Coronary veins were semi-automatically segmented to construct a 3D model. CTA-derived coronary venous anatomy was compared with intra-procedural fluoroscopic angiography (FA) in right and left anterior oblique views.

Results

Coronary venous CTA was successfully performed in all 18 patients. CRT implantation and FA were performed in 15 patients. A total of 62 veins were visualised; the number of veins per patient was 3.8 (range: 2–5). Eighty-five per cent (53/62) of the veins were visualised on both CTA and FA, while 10% (6/62) were visualised on CTA only, and 5% (3/62) on FA only. Twenty-two veins were present on the lateral or inferolateral wall; of these, 95% (21/22) were visualised by CTA. A left-sided implantation was performed in 13 patients, while a right-sided implantation was performed in the remaining 2 patients because of a persistent left-sided superior vena cava with no left innominate vein on CTA.

Conclusion

Imaging of the coronary veins by CTA using a designated protocol is technically feasible and facilitates the CRT implantation approach, potentially improving the outcome.

     

Balloon Venoplasty of Subclavian Vein and Brachiocephalic Junction to Enable Left Ventricular Lead Placement for Cardiac Resynchronisation Therapy

This report describes the successful implantation of a LV lead using balloon venoplasty to overcome a very tight stenosis of the right subclavian vein / brachiocephalic junction for cardiac resynchronisation therapy (CRT-P) in a patient with a right sided CRT-P system and a failed epicardial LV lead. It is important for device implanters to be familiar with interventional equipments and techniques such as balloon venoplasty to overcome difficult venous access.     

Overcoming a subclavian complete occlusion: Simple single lead extraction by the subclavian vein allowing implantation of two new leads and upgrade to CRT-P with multi-site pacing

Central venous obstruction following pacemaker implantation is not uncommon, and can prove challenging in the case of system upgrade. We report a case of DDDR to CRT-P (with multi-site pacing) upgrade, where a subclavian occlusion was overcome resorting to an atrial lead extraction (using only a locking stylet). This allowed regaining of the venous access with subsequent implantation of not just one, but two new leads and subsequent successful upgrade.     

Endocardial pacemaker implantation in neonates and infants

Transvenous pacemaker lead implantation is the preferred method of pacing in adult patients. Lead performance and longevity are superior and the implantation approach can be performed under local anaesthetic with a very low morbidity. In children, and especially in neonates and infants, the epicardial route was traditionally chosen until the advent of smaller generators and lead implantation techniques that allowed growth of the child without lead displacement. Endocardial implantation is not universally accepted, however, as there is an incidence of venous occlusion of the smaller veins of neonates and infants with concerns for loss of venous access in the future. Growing experience with lower profile leads, however, reveals that endocardial pacing too can be performed with low morbidity and good long-term results in neonates and infants.     

Transcatheter leadless permanent pacemaker in complex congenital heart disease with interrupted inferior vena cava: A challenging implantation

31 years lady with complete atrioventricular canal defect, large primum atrial septal defect (ASD), inlet ventricular septal defect (VSD) and Eisenmenger syndrome, presented with atrial flutter and complete heart block. She was not suitable for corrective cardiac surgery and not yet indicated for heart-lung transplantation. She was advised single chamber permanent pacemaker and eventually Micra VR transcatheter leadless pacemaker was finalised for her. Transcatheter leadless pacemaker was deployed in her RV septum despite some unforeseen technical problems. This patient had intrahepatic interruption of IVC with Azygous continuation draining into SVC but this altered venovascular course was detected only fluoroscopically midway during the pacemaker implantation procedure and this was not detected in the preprocedural transthoracic echocardiography. This abnormal venous course was clearly demonstrated in the cardiac CT which was performed only after completion of the pacemaker implantation procedure in this patient. The technical challenges encountered mainly were mostly during the manipulation of the 27F delivery catheter of Micra through this altered cardiovascular anatomy via transfemoral approach and also due to the presence of septal defects. Thus, transcatheter leadless permanent pacemaker was implanted successfully through transfemoral access in this complex congenital heart disease with interrupted IVC and azygous continuation. Besides transthoracic echocardiography, it may be better to perform transesophageal echocardiography or even preferably radiological imaging like cardiac CT or MRI prior to transcatheter leadless pacemaker implantation in patients with complex congenital heart disease to understand the cardiovascular anatomy and plan the procedure.     

Implantation of a resynchronization implantable cardioverter defibrillator in a patient with persistent left superior vena cava

Implantation of resynchronization implantable cardioverter defibrillator was performed in a patient with persistent left superior vena cava. A dual coil defibrillation lead was inserted in the right ventricle apex via a small innominate vein. Left ventricular and atrial leads were implanted through persistent left superior vena cava. Left ventricular lead was easily implanted into the postero lateral vein. Pacing thresholds and sensing values were excellent and remained stable at 18 months follow-up.Presence of persistent left superior vena cava generally makes transvenous lead implantation difficult. However when a favorable coronary sinus anatomy is also present, it may facilitate left ventricular lead positioning in the coronary sinus branches.     

Treatment of Pacemaker-Induced Superior Vena Cava Syndrome by Balloon Angioplasty and Stenting

Superior vena cava (SVC) syndrome is a rare but serious complication after pacemaker implantation. This report describes three cases of SVC syndrome treated with venoplasty and venous stenting, with an average follow-up of 30.7 (±3.1) months. These cases illustrate that the definitive diagnosis, and the extent and location of venous obstruction, can only be determined by venography.     

Three-dimensional fetal echocardiography

The complex anatomy and dynamics of the heart make it a challenging organ to image. The fetal heart is particularly difficult because it is located deep within the mother's abdomen and direct access to electrocardiographic information is difficult. Thus more complex imaging and analysis methods are necessary to obtain information regarding fetal cardiac anatomy and function. This information can be used for medical diagnosis, model development and theoretical validation. The objective of this article is to provide scientists and engineers with an overview of three-dimensional fetal echocardiography.     

Anatomy of the crocodilian spinal vein

The crocodilian spinal vein is remarkably robust yet historically overlooked. Using corrosion casting, we describe the anatomy of this vessel and its connections with the caval and hepatic venous systems in representatives from four crocodilian genera. The spinal vein arises from an enlarged occipital sinus over the medulla and extends the entire length of the vertebral column. Unlike in squamate reptiles, the spinal vein is single (nonplexiform), voluminous, and situated dorsal to the spinal cord, and plexi lateral to the cord span between emerging intercostal veins. The connections with the other venous systems are otherwise similar to those in other tetrapods. The overall anatomy of this vessel and its abundant connections with the other venous systems indicate it likely plays a primary role in returning blood to the heart from all parts of the body. Preliminary studies of function suggest that this vessel could also play an adaptive role during basking and diving.     

Eliminating the "Pitfalls" of chronic indwelling central venous access device placement in cancer patients by utilizing a venous cutdown approach and by selectively and appropriately utilizing intraoperative venography

There are several very obvious and simple solutions for eliminating the "Pitfalls" and for minimizing the risk of occurrence of any perioperative complications associated with placement of chronic indwelling central venous access devices in cancer patients. The first is the utilization of a venous cutdown approach, such as the cephalic vein or the external jugular vein, which essentially eliminates potentially life-threatening perioperative complications, such as pneumothorax and injury to the great vessels (with or without associated hemothorax). The second is the selective and appropriate utilization of intraoperative venography for defining the central venous anatomy and for providing a venous roadmap in those particularly challenging cases in which difficulties are encountered during chronic indwelling central venous access device placement.     

An unusual ‘bow tie’ image in pacemaker implantation

Upper venous system anatomic variations may cause difficulties during cardiac pacemaker implantation. Persistent left superior vena cava (PLSVC) and absent right superior vena cava could be an arrhythmogenic source of atrial arrhythmias and cardiac conduction disease. We represent dual-chamber pacemaker implantation in a patient with a very rare upper venous system anomaly, paroxysmal atrial fibrillation, sick sinus syndrome, that cause unusual fluoroscopic image.     

Transvenous pacing in complex post-operative congenital heart disease guided by angiography: A case report

Transvenous pacing in patients with postoperative complex congenital heart disease (CHD) can be challenging and pose technical challenges to lead placement because of the complex anatomy, distortions produced by the surgical procedures, and the altered relationship of cardiac chambers. We describe the utility of angiography for transvenous dual chamber pacemaker implantation in a post-operative complex congenital heart disease.     

Transvenous pacing through the pulmonary valve in a patient with cyanotic congenital heart disease after Glenn shunt – A case report

Bradyarrhythmia requiring pacing is infrequently encountered in patients with complex cyanotic congenital heart disease. Even though epicardial pacing is the preferred mode, rarely, a need for endocardial lead implantation arises.Patients with cavopulmonary shunts limit access to the venous atria and ventricles, necessitating alternate methods of pacemaker implantation. We report transvenous endocardial lead implantation by an unconventional method in a patient with congenitally corrected transposition of great arteries after a bidirectional Glenn shunt.     

Data regarding the typology and functional significance of the venous valves

Many authors described in detail the morphological features of human venous valves, but less their functional architecture. The present study provides additional information concerning the valvular anatomy, to enable its functional interpretation. The previously reported data and the author's results showed the regional distribution and characteristics of venous valves in different areas of the human body. Certain findings suggested a reorganization after birth of the venous valves which are frequently met in fetus. The close relation between hemodynamic mechanisms and the blood guiding structures may explain the changes (disappearance or persistence) of venous valves in some areas after birth. Significance of the rudimentary folds, resembling valves, is not yet elucidated. Based on his observations, the author attempted a new classification of the veins. The relations between density and morphological peculiarities of venous valves in different vein types showed that the constant valves were always involved in the local hemodynamics. Bardeleben's principles referring to the location and topographical arrangement of venous valves can be applied only to certain areas of the limbs, but not to other regions. In this paper there are described and functionally interpreted the venous valves of all territories of the human body.     

Coronary sinus of the heart in various anomalies of the conotruncus

Thirty-one hearts with anomalous conotruncus (common arterial trunk, hypoplasia of the aorta with transposition, atresia of the pulmonary trunk) have been studied. There are some peculiarities in anatomy and topography of the coronary sinus, concerning its sources, that is veins forming the venous sinus, position and interrelations with the venous sulcus and with the interatrial septum, size and form of the ostium and valve of the coronary sinus. The most amount of the anatomical peculiarities of the sinus are observed in the preparations, where the anomalous conotruncus is combined with absence of one or both cardiac septa.     

Internal Jugular/Subclavian Venous Access In Electrophysiology Study And Ablation

Multiple venous accesses are required for catheter placement during electrophysiology study and ablation. Internal jugular/subclavian venous access, though restricted nowadays, can be important in difficult situations.     

A precise radiographic technique for the measurement of dimensional changes in heart valve biomaterials following fixation

Accurate tissue thickness measurements are difficult to acquire by present techniques. Error is introduced by tissue compression during measurements or by tissue processing prior to measurement. In the field of valve replacement, tissue dimensional changes from fixation prior to implantation may predispose implants to premature tissue failure and it becomes important to have an accurate method for comparing cusp dimensions pre- and post-fixation. A new approach is to use high-resolution digital radiography to make thickness maps of entire specimens. For 25 matched porcine aortic valve cusps, we have evaluated this technique's ability to measure and compare thickness, surface area and volume before and after 7 days of aldehyde fixation. Digital radiographs were acquired pre- and post-0.5% glutaraldehyde (n=13) or 10% formaldehyde (n=12) fixation. Mean thickness, surface area, volume and four measurements to evaluate shape differences with fixation were obtained and compared pre- and post-fixation using paired t tests. The results demonstrate that this X-ray imaging technique can provide dimensions of matched fresh and fixed specimens and is sensitive enough to show statistically significant changes due to fixation. These findings also illustrate that aldehyde fixation can cause tissue contraction resulting in a significant overall increase in tissue thickness and a decrease in surface area. This technique could be used to gain further insights into tissue anatomy and mechanics.     

Medial canthal reconstruction using a medially based upper eyelid myocutaneous flap

Periorbital reconstruction following skin cancer ablation represents a challenging problem. A thorough understanding of the complex periorbital anatomy is necessary to preserve lid function and protect the ocular surface. The medial canthal region represents the most difficult periorbital zone to reconstruct. This area has a complex anatomy involving both the medial canthus itself and the lacrimal apparatus. The authors present their experience with a versatile technique for reconstruction of the medial canthal periorbital region, namely, a medially based upper eyelid myocutaneous flap. In the 10 patients in whom this procedure was used, there was one partial and no complete flap losses. The authors believe that the medially based upper lid myocutaneous flap offers an excellent solution to the difficult problem of medial canthal periorbital reconstruction.