Improved quality of life after treatment of prolonged asystole during breath holding spells with a cardiac pacemaker brain anoxia

INTRODUCTION

Breath-holding spells (BHS), amongst other seizure-like episodes in childhood, are mostly harmless events in otherwise healthy pediatric populations. In contrast to these simple infrequent BHS, mostly without loss of consciousness (LOC), some patients suffer from a more severe form of BHS.[ 1] the latter variant is characterized by very frequent spells and LOC. The estimated prevalence of these severe BHS is about 0.6-4%.[ 2] although the exact pathophysiology remains unknown, most authors differentiate between two basic mechanisms resulting in either pallid (pbhs) or cyanotic (cbhs) BHS.


Both start with a provoking stimulus (pain, anger, or fright), resulting in emotional upset, which finally leads to a state of noiseless expiration.Brain anoxia in pbhs, the asystole that follows is thought to result from exuberant vagally mediated cardiac inhibition [ figure 1]. CBHS result in a condition in which the child is finally unable to relax and inhale and thus becomes apneic and cyanotic. Both entities may lead to LOC and hypoxic seizures.[ 3, 4, 5, 6, 7, 8] twenty-four–hour holter monitoring and implantable loop recorders allow an effective distinction between both mechanisms.[ 9, 10, 11, 12, 13] experiencing pbhs is often dramatic and terrifying for both patient and parents or siblings. A peak frequency of several episodes per day represents a major stress factor for affected families. Although both pbhs and cbhs are self-limiting conditions and there is no death reported in the current literature, there are no data available concerning the effect of frequent BHS with LOC on long-term neurologic outcome in affected individuals.Brain anoxia single- as well as dual-chamber cardiac pacing was reported to be effective in patients with BHS and asystole by stephenson et al. (1999) and di pino et al. (2007).[ 14, 15] nonetheless, there continues to be some controversy about this treatment option since the implantation of a cardiac pacemaker (PM) in a child is an invasive method involving several risks. Consequently, this study aims to discuss and evaluate the assets and drawbacks of cardiac pacing in pediatric patients with prolonged asystole during BHS.

MATERIALS AND METHODS

Clinical data of patients who were presented to the department for pediatric cardiology, heart center leipzig in 2001–2013 with BHS were collected retrospectively.Brain anoxia patients who fulfilled our center’s internal criteria for PM implantation, i.E., symptomatic patients with BHS and prolonged asystole, defined as multiple (3) detected episodes of asystole lasting more than 10 seconds each, were included. Symptoms, onset of spells, age at first consultation, as well as surgical records and clinical follow-up data were reviewed. Long-term follow-up data were obtained from patient records and correspondence with parents. Written consent was obtained from all parents.

Quality of life (QOL) questionnaire: A standardized questionnaire on QOL, stress levels of parents and patients (as reckoned by the parents), before and after PM implantation, was compiled by all parents of the children included in this study.Brain anoxia the initial questionnaire was completed one day before PM implantation. The second questionnaire was completed at least three months after PM implantation.

Demographics of patients treated with a pacemaker for breath-holding spells

Before PM implantation, all patients suffered from frequent LOC during episodes of BHS. Mean frequency of symptomatic spells including LOC was 1.4 per day with up to 5 episodes per day in the most severe case. This patient was also resuscitated once after suffering LOC due to BHS during hospitalization (patient 7). One patient showed symptoms rather infrequently, usually when experiencing sudden pain, and suffered minor head injury when collapsing once (patient 6).

Brain anoxia

After admission, a physical examination, 12-lead ECG, echocardiography and holter recording were performed. No signs of structural heart defects were observed. Asystole was detected by holter recording in six cases; in one case, a medtronic REVEAL implantable loop recorder had already been implanted at another hospital. ECG data showed tachycardia at the beginning of the spell, followed by bradycardia and temporary asystole. No other signs of cardiac arrhythmia, i.E., AV block, prolonged QT duration, or pre-excitation were observed.

PM implantation followed 1 week–13 months after first consultation. Mean age at implantation was 23 months (8 months–3.9 years). Six patients received epicardial-pacing leads using a subxiphoid approach.Brain anoxia in one case transvenous PM implantation was performed. All patients had VVI pacing with 100–110 beats per minute (BPM) and search hysteresis of 40–50 BPM to allow for spontaneous rhythm in between the asystole episodes. All patients were followed up every 6 months for a mean period of 4.06 years (range, 7 months–7.7 years). No PM related adverse events were recorded.

Table 2 summarizes the subjective stress levels of patients and parents before and after PM implantation, as well as the influence of the spells on everyday life as reported by the patients’ parents. Paired t-testing showed a significant reduction in parental stress (mean 3.0, CI 1.24–4.76, P = 0.007, test power 0.92), patients stress levels (mean 1.83, CI 0.61–3.06, P = 0.012, test power 0.85), as well as improvement in everyday QOL (mean 1.83, CI 0.61–3.06, P = 0.012, test power 0.85).Brain anoxia

DISCUSSION

There is an ongoing controversy regarding the indication for cardiac PM implantation as a treatment option in patients with BHS. While BHS is generally considered a self-limiting disease with a reported mortality rate of 0%, it is often a dramatic and terrifying experience, putting patients and families under severe psychological strain. In addition, until now, no data were collected on the long-term effect of frequent (3) episodes per week of BHS with presyncope or syncope on the neurodevelopmental outcome in these patients. As LOC and associated seizures are believed to arise from hypoxia caused by cerebral hypoperfusion, it seems a logical conclusion that repeated episodes of symptomatic cerebral hypoperfusion are not beneficial for the affected patient.Brain anoxia reviewing literature on current BHS treatment strategies, it becomes apparent that some confusion arises from the varying definitions of BHS, where some definitions focus on clinical aspects, other focus on the pathophysiology, and only few definitions respect LOC or seizures.[ 16, 17, 18, 19] nevertheless, it is beyond dispute that mild courses of BHS without LOC or very infrequent episodes do not need treatment because the disease is benign and the condition itself will mostly resolve by the age of five years. Apart from these benign causes of BHS, the treatment of those patients with very frequent spells including frequent LOC remains challenging.

This study focuses on patients with BHS with LOC and documented prolonged asystole with regard to the effect of PM implantation on patients’ symptoms and patient/parental QOL.Brain anoxia to the best our knowledge, this study presents the first data on QOL before and after PM implantation in this group of patients.

Concerning psychological stress experienced by the affected families, mattie-luksic et al. (2000) showed that mothers of children with BHS experienced more overall stress and disruption in their attachment or understanding of their child and showed significant more disruption in their sense of competence as a parent compared to mothers of children without seizure disorders.[ 20] similarly, our results showed a marked decrease in patient as well as parental stress. In addition, a decrease in limitations of everyday life after successful elimination of BHS-related symptoms can be seen from the data.Brain anoxia parents reported their own stress level to be higher than that of their children.

Apart from reducing parental stress, permanent pms are reported to effectively protect patients from further LOC and reduce near-miss events during BHS with asystole. As reported by mcleod et al. (1999) who compared placebo versus VVI vs. DDD pacing in 12 children with BHS and asystole with LOC, both dual-chamber and single-chamber pacing significantly reduced the number of syncopal episodes compared with placebo. VVI was as effective as DDD for preventing syncope, but DDD was superior to VVI in reducing near-miss events. Included were patients with asystole duration of 10-40 seconds. DiPino et al. (2006) reported immediate resolution of spells in one patient with BHS and asystole of 26 seconds after PM implantation.Brain anoxia the same was reported by kanjwal et al. (2009) in another patient with BHS and asystole of 20 seconds. Kelly et al. (2001) reported their experiences with 10 patients. They found an immediate resolution of spells in five and prevention from LOC in two patients. Three nonresponders were reported, all of them with either only severe bradycardia or relatively short asystole of maximum 6.8 seconds.

Our results underline the effectiveness of cardiac pacing in patients with BHS and prolonged asystole. Looking at those patients who did not respond immediately to therapy, two basic mechanisms seem to be involved. Firstly, a critical duration of asystole is needed to be the only major cause of the LOC and thereby can be effectively prevented by cardiac pacing.Brain anoxia secondly, correct PM settings are needed to prevent symptoms. Cardiac PM settings should be chosen to provide stimulation only in case of asystole and avoid excessive ventricular stimulation. In addition, cardiac PM not only has to compensate for the asystole but also provide enough cardiac output to balance out the effect of lowered blood pressure by vagally mediated vasodilation, which is also present to various extents during BHS. Following the experience in our center, the most appropriate setting is VVI pacing at 100-110 BPM and a repetitive hysteresis of about 40-50 BPM depending on the patient’s age [ figure 2]. As shown in the presented data, these settings effectively prevented episodes of LOC in 6 out of 7 patients and significantly limited the number of spells that were associated with LOC.Brain anoxia as mentioned above, there was one nonresponder in our group. This patient (number 7) suffered from ongoing spells including seizures and LOC despite PM implantation and optimization of PM settings. In this patient the spells switched from BHS with asystole to cyanotic spells. We speculate that the associated central nervous system disorder may have an additional influence on the clinical picture.