Pacemaker Use in New Zealand - Data From the New Zealand Implanted Cardiac Device Registry (ANZACS-QI 15).

BACKGROUND: The New Zealand Cardiac Implanted Device Registry (Device) has recently been developed under the auspices of the New Zealand Branch of the Cardiac Society of Australia and New Zealand. This study describes the initial Device registry cohort of patients receiving a new pacemaker, their indications for pacing and their perioperative complications. METHODS: The Device Registry was used to audit patients receiving a first pacemaker between 1st January 2014 and 1st June 2015. RESULTS: We examined 1611 patients undergoing first pacemaker implantation. Patients were predominantly male (59%), and had a median age of 70 years. The most common symptom for pacemaker implantation was syncope (39%), followed by dizziness (30%) and dyspnoea (12%). The most common aetiology for a pacemaker was a conduction tissue disorder (35%), followed by sinus node dysfunction (22%). Atrioventricular (AV) block was the most common ECG abnormality, present in 44%. Dual chamber pacemakers were most common (62%), followed by single chamber ventricular pacemakers (34%), and cardiac resynchronisation therapy - pacemakers (CRT-P) (2%). Complications within 24hours of the implant procedure were reported in 64 patients (3.9%), none of which were fatal. The most common complication was the need for reoperation to manipulate a lead, occurring in 23 patients (1.4%). CONCLUSION: This is the first description of data entered into the Device registry. Patients receiving a pacemaker were younger than in European registries, and there was a low use of CRT-P devices compared to international rates. Complications rates were low and compare favourably to available international data.

Permanent pacemaker implantation via the femoral vein: an alternative in cases with contraindications to the pectoral approach.

BACKGROUND: This paper presents a consecutive series of permanent pacemakers (PPM) implanted via the femoral vein in patients with contraindications to pacing systems via the superior vena cava (SCV). The femoral vein approach is a less invasive and feasible alternative to epicardial lead placement. METHODS: Twenty-seven patients had femoral pacemakers inserted. Indications for femoral vein pacemaker insertion were: SVC/subclavian obstruction (12 patients, 44.4%), previous infection in SVC leads (four patients, 14.8%), mastectomy and/or radiotherapy to chest (four patients, 14.8%), multiple leads in SVC (two patients, 7.4%), recurrent erosion (two patients, 7.4%), abnormal anatomy (one patient, 3.7%), painful pacemaker pocket (one patient, 3.7%) and burns (one patient, 3.7%). Fifty-one leads, 25 atrial and 26 ventricular, were inserted. The majority of leads were active fixations (96% of atrial leads and 85% ventricular leads). RESULTS: During a mean follow-up of 36.5 months (range 0.9-116.5), six additional unplanned procedures were performed in four patients. Atrial lead displacement occurred in five leads (20%). There were no ventricular lead displacements. In two patients, box revision for pre-erosion was required. One patient had persistent pain at the site of abdominal pacemaker generator. Infection, thromboembolic events, thromophlebitis, evidence of lower limb venous occlusion and lead fracture did not occur. CONCLUSION: Femoral vein PPM are a simple and feasible alternative in patients in whom the SVC approach is contraindicated.

Syncope.

Syncope is a common clinical presentation. Although most commonly benign, it may herald a pathology with a poor prognosis. The work-up of syncope includes a careful history, physical examination, electrocardiogram, risk stratification, and appropriately directed testing. The key factor in the investigation of syncope is the presence (or absence) of structural heart disease or an abnormal electrocardiogram. The most useful investigation in unexplained syncope with a normal heart is the tilt table test for evaluating predisposition to neurocardiogenic (vasovagal) syncope. In the setting of structural heart disease or an abnormal electrocardiogram, electrophysiologic studies play a more important role. The utility of noninvasive cardiac monitoring for symptom-rhythm correlation may be limited by infrequent symptoms. The availability of external and implantable loop recorders allows prolonged periods of monitoring to increase diagnostic yield. The management of patients with syncope may be complex. Early referral to a cardiac electrophysiologist is warranted in patients who are at high risk.

Pacemaker lead related tricuspid stenosis: a report of two cases.

Only four cases of tricuspid stenosis related to endocardial pacemaker leads have been reported. Two further cases associated with perforation of a tricuspid valve leaflet by a pacemaker lead are presented: a 46 year old woman and a 60 year old man. It is possible that tricuspid valve disease related to endocardial pacemaker and non-thoracotomy defibrillator leads is underrecognized. Diagnosis requires clinical suspicion and the use of Doppler echocardiography. Recent evidence of fibrosis affecting the tricuspid valve in hearts from patients who have had non-thoracotomy defibrillator implants suggests that this problem could be more common in the future.

Cardioinhibition during tilt testing identifies patients who may benefit from pacing.

UNLABELLED: This study examined whether the various hemodynamic collapse patterns observed during tilt testing in patients with suspected neurocardiogenic syncope are relevant when planning therapy, particularly whether a predominantly cardioinhibitory response predicts a beneficial response from pacing. METHODS: The effects of temporary atrioventricular (A-V) sequential pacing were studied during tilt testing in 34 patients 48.2 +/- 18.5 years of age. The patient population was divided into a cardioinhibitory group (VASIS classes 2A and 2B) or mixed group (VASIS classes 1 and 3) according to their response to baseline tilt testing. The test was then repeated during A-V pacing with rate hysteresis. A positive response to A-V pacing was defined as a > or = 30-second increase between onset of symptoms and syncope, or mitigation of symptoms compared with the baseline tilt test. RESULTS: The study protocol was not successfully completed in three patients. Among the remaining 31 patients, a baseline cardioinhibitory response was observed in 17, and a mixed response in 14 patients. A-V sequential pacing was successful in 13 of 17 patients with a cardioinhibitory response versus 5 of 14 patients with a mixed response (P = 0.024). CONCLUSION: The presence of a predominantly cardioinhibitory collapse pattern (VASIS 2A and 2B) during baseline tilt testing doubled the likelihood of successful temporary A-V sequential pacing, and may identify patients with neurocardiogenic syncope most likely to benefit from permanent dual chamber pacing.

Determining the optimal pacing intervention rate for vasovagal syncope.

INTRODUCTION: In this study, patients with rate hysteresis pacemakers implanted for vasovagal syncope were re-studied using serial tilt testing to determine whether, once triggered, pacing was more effective if the intervention rate was higher than the standard rate. METHODS AND RESULTS: Twenty patients (mean age 55.4 years, range 23-81, 14 male) were studied, with randomisation to either initial standard rate (80-90 beats/min) intervention, or to initial high rate (120 beats/min) intervention. Although 18 of the 20 reported complete abolition of syncope since pacing, only 8 patients could be objectively assessed. The respective mean time to tilt down after symptom onset with standard and high rate intervention was 193+/-234s and 185+/-143s, (P>0.05). CONCLUSION: Repeat tilt testing was only of limited value in assessing the benefit of pacing. There was no advantage with high rate intervention in delaying the loss of consciousness (or intolerable symptoms) after the initial onset of symptoms.

Sudden death in a child with an unusual accessory connection.

An 8-year-old boy with Wolff-Parkinson-White syndrome died suddenly whilst exercising. He had been well with no immediate preceding symptoms of an arrhythmia, and was receiving no drugs. As an infant he had suffered recurrent episodes of atrioventricular reciprocating tachycardia (AVRT) and had documented pre-excited atrial fibrillation. At electrophysiological (EP) study, the refractory periods of his two accessory pathways were less than 220 ms. Drugs were discontinued at 4 years of age when he remained asymptomatic. Autopsy confirmed a very unusual accessory pathway. It was a muscular connection between the base of the right atrial appendage and the right ventricle, distant from the annulus of the tricuspid valve.

Mode switching for atrial tachyarrhythmias.

Mode switching for atrial tachyarrhythmias is a concept that originated from use of DDI mode and was introduced in the early 1990s to prevent dual-chamber pacemakers from ventricular tracking of rapid atrial rates. This article describes the currently available systems and discusses the advantages and disadvantages of the technique. The results of a preliminary randomized controlled trial of 1 algorithm and plans for a second study are presented.