An Initiative Technique to Facilitate Axillary Vein Puncture During CRT Implantation.

OBJECTIVES: The aim of the study was to describe a new technique to minimize requirement of contrast and the time to puncture the axillary vein during implantation of cardiac resynchronization therapy (CRT) devices. BACKGROUND: One of the challenges to the wide applications of CRT has been the technical difficulty encountered while obtaining venous access utilizing axillary venous puncture. This is mainly due to vague anatomical land marks. The axillary vein is the preferred access point because of fewer associated risks and better lead protection in the future. METHODS: We introduced a 0.035 mm guidewire retrogradely from the femoral vein up to the left axillary vein. A single anteroposterior scene at 7.5 frames/second was captured while the guidewire was in the vein. The scene was kept as a roadmap for the axillary vein puncture during the implantation procedure. RESULTS: The axillary vein was accessed in all patients (100%) and the time to axillary vein puncture was <1 minute in 36 patients (41%) and between 1-5 minutes in the remaining patients. There were no related vascular complications and no contrast venography was required. CONCLUSION: The use of retrograde axillary vein wiring simplifies axillary venous puncture and minimizes the need for contrast media during CRT device implantation without compromising visualized anatomy.

Simultaneous antegrade dual AV node conduction initiates AV nodal re-entrant tachycardia (a rare initiation mechanism).

Typical atrioventricular nodal reentrant tachycardia (AVNRT) is the most common paroxysmal supraventricular tachycardia among adults. The concept of dual pathway physiology remains widely accepted, although this physiology likely results from the functional properties of anisotropic tissue within the triangle of Koch, rather than anatomically distinct tracts of conduction. AVNRT is typically induced with anterograde block over the fast pathway and conduction over the slow pathway, with subsequent retrograde conduction over the fast pathway. On rare occasions, anterograde AV node conduction occurs simultaneously through fast and slow pathways resulting in two ventricular beats in response to one atrial beat. We report a case of AVNRT where the tachycardia is always induced by the same mechanism described above. Successful ablation was achieved by slow pathway modification.

The ECG role in identifying the etiology of tachycardia-induced cardiomyopathy (TIC).

Tachycardia-induced cardiomyopathy (TIC) is a well recognized entity of heart failure (HF) and various mechanisms due to tachyarrhythmias have been postulated to be responsible for impaired cardiac contractility. Previously reported cases showed reversibility of such disorders whenever stable cardiac rhythm is maintained adequately and we report on a 16-year-old boy who has been diagnosed to have TIC, which was misinterpreted initially as sinus tachycardia secondary to dilated cardiomyopathy and heart failure. A complete recovery of his left ventricular function was achieved by radiofrequency catheter ablation and highlights the importance of a 12-lead electrocardiogram (ECG) assessment in such patients.

Coronary sinus diverticulum as a cause of resistant posteroseptal pathway ablation.

Coronary sinus (CS) anomalies such as diverticulum, persistent left superior vena cava or CS ostium dilatation are predominantly found in patients with accessory pathway-related tachycardias. Diverticulum of the proximal CS found in 7-11% of patients with postero-septal or left posterior manifests accessory pathways. We reported a 28 year old gentleman with manifested postero-septal accessory pathway, who underwent repeat electrophysiological study (EPS) and radiofrequency ablation for previously failed ablation. Huge CS diverticulum was identified by angiography as a reason for resistant accessory pathway. Successful RF ablation was achieved at the neck of the diverticulum without complications. Other associated anomalies were ruled out by cardiac computerized tomography (CT) and trans-esophageal echocardiography.

The importance of utilizing 24-h Holter monitoring as a non-invasive method of predicting the mechanism of supraventricular tachycardia.

Despite the emergence of advanced invasive technology in identifying the various types of arrhythmia mechanisms, 24-h ambulatory electrocardiogram monitoring as a non-invasive method remains an invaluable informative tool in delineating such mechanisms. Furthermore, one observational study has supported the utilization of 24-h Holter monitoring in exploring AV Node (AVN) characteristics sufficiently in correlation with invasive studies when limited to patients without Wolf Parkinson White syndrome showing a positive predictive value of 98% in their supraventricular tachycardia (SVT) assessment (Fukuda et al., 2005). We describe in this report suspected tachycardia initiation mechanism in three SVT cases based on 24-h Holter recordings. Premature atrial contraction with subsequent AVN fast pathway conduction block initiated the common type AVN re-entrant tachycardia (AVNRT). Dual AVN physiology was documented during the electrophysiological studies in all three cases and a definitive therapy was achieved by the AVN slow pathway modification.

Controlling rate and rhythm increases feasibility of CT angiography in atrial fibrillation.

A woman, aged 48 years, with severe rheumatic mitral stenosis and uncontrolled permanent atrial fibrillation (AF) underwent preoperative assessment of coronary arteries. Invasive coronary angiography was not possible because of occluded common iliac artery and bilateral radial spasm. Transesophageal echocardiogram showed a very large mobile left atrial appendage clot, precluding cardioversion. The severe motion artifacts during cardiac CT angiography (64 slices) due to atrial fibrillation were overcome by controlling rhythm and rate through insertion of a temporary pacemaker via right femoral vein, and slowing heart rate below 65 beats per minute by intravenous metoprolol (25 mg) and verapamil (5 mg). Clear pictures of all coronary arteries as well as the left atrial appendage clot were obtained. The temporary pacemaker was removed after eight hours. Uneventful mechanical mitral valve replacement and maze procedure were performed and the patient was discharged in a stable condition.

Maneuvering balloon occlusion technique to deflect LV lead into a target branch during CRT implantation.

Implantation of specifically designed left ventricular (LV) lead is a relatively complex procedure that depends on the anatomy of the coronary veins, available instrumentation, and experience of the operator. In patients with dilated cardiomyopathy (DCM) tortuosity of the selected branch of coronary sinus (CS) leads to difficult or failed LV placement. A case study of a 45-year-old woman with DCM requiring lead placement is presented here. To plan for proper LV lead positioning, CS angiography was obtained through right femoral vein approach with preshaped long sheath (SJM, SL3) and occlusive balloon. For successful implant of LV lead, with no viable alternatives available, the tortuosity of the lateral and posterolateral branch were overcome by advancing and inflating the balloon in the main CS to deflect LV lead into the target branch. A unipolar LV lead (Medtronic 4193) was finally placed in a true posterolateral position with excellent sensing and pacing threshold without phrenic nerve stimulation.

Neonatal meningitis.

OBJECTIVE: To determine the prevalent bacterial agents of neonatal meningitis and their antibiotic susceptibility in a referral intensive care unit in Assir Central Hospital, Saudi Arabia, during the years 1993-1998. METHODS: Records of newborn infants with positive cerebrospinal fluid culture during the period were retrospectively studied. RESULTS: There were 1473 nursery admissions, of which 32 episodes of meningitis occurred amongst 31 neonates. Klebsiella pneumoniae (31%) and Serratia marcescens (21%) were the main pathogens. The incidence of concurrent septicemia among these infants was 58%. Klebsiella pneumoniae appears to dominate in both early and late onset infections. The sex incidence was equal and the mortality rate was 48%. CONCLUSION: The survey identifies Klebsiella pneumoniae and Serratia sp. as the leading bacterial agents of neonatal meningitis in our environment. The relatively high frequency of Serratia infection in the present survey appears unique as this organism is comparatively rare in other reports across the globe. No Group B Streptococcus was isolated, which is in contrast to reports obtained in Europe, America and Australia where it is the predominant organism of neonatal sepsis or meningitis. Antibiogram identified imipenem and cefotaxime as the empirical antibiotics in infants with a clinical diagnosis of neonatal sepsis in our hospital; no more conventional use of ampicillin. In view of the changing bacterial pattern of infant infection with time even in the same environment, a periodic review of this subject is advocated.

Neonatal meningitis.

OBJECTIVE: To determine the prevalent bacterial agents of neonatal meningitis and their antibiotic susceptibility in a referral intensive care unit in Assir Central Hospital, Saudi Arabia, during the years 1993-1998. METHODS: Records of newborn infants with positive cerebrospinal fluid culture during the period were retrospectively studied. RESULTS: There were 1473 nursery admissions, of which 32 episodes of meningitis occurred amongst 31 neonates. Klebsiella pneumoniae (31%) and Serratia marcescens (21%) were the main pathogens. The incidence of concurrent septicemia among these infants was 58%. Klebsiella pneumoniae appears to dominate in both early and late onset infections. The sex incidence was equal and the mortality rate was 48%. CONCLUSION: The survey identifies Klebsiella pneumoniae and Serratia sp. as the leading bacterial agents of neonatal meningitis in our environment. The relatively high frequency of Serratia infection in the present survey appears unique as this organism is comparatively rare in other reports across the globe. No Group B Streptococcus was isolated, which is in contrast to reports obtained in Europe, America and Australia where it is the predominant organism of neonatal sepsis or meningitis. Antibiogram identified imipenem and cefotaxime as the empirical antibiotics in infants with a clinical diagnosis of neonatal sepsis in our hospital; no more conventional use of ampicillin. In view of the changing bacterial pattern of infant infection with time even in the same environment, a periodic review of this subject is advocated.

Congenital hydrocephalus due to aqueductal stenosis of probable autosomal recessive inheritance.

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