Rare case of CNS related bradycardia and syncope: Case report

UK: Dr Dmitri Pchejetski at James Paget University Hospital, Great Yarmouth, Norfolk, UK and colleagues have reported a case of presenting as syncope and bradycardia. The case has been published in the Journal of Medical Case Reports.

In the presence of bradycardia or abnormal heart rhythms, syncope is often investigated in the context of these changes and the most common causes are cardiac arrhythmias, obstructive cardiac lesions, structural cardiopulmonary disease, sick sinus syndrome, Adams–Stokes syndrome, subclavian steal syndrome, or aortic dissection. This case highlights the importance of considering other causes of syncope (such as metabolic or CNS related) even in the presence of cardiac findings

A 69-year-old Caucasian man came to A&E complaining of episodes of lightheadedness. He described a sensation beginning in his feet, spreading upwards, and then becoming lightheaded, hot, and clammy. Each episode lasted for a few minutes. The episodes occurred randomly in the past year, were not provoked by any stimuli, and there were no focalized neurological symptoms.

In general, he had felt unwell for the past year, feeling tired and weak, had reduced appetite, but no weight loss.

He had a past medical history of hypertension treated with ramipril. He was previously investigated for ischemic heart disease with an exercise tolerance test that was negative for ischemic changes and a 90% predicted heart rate was achieved. His echocardiogram showed good global systolic and diastolic function. He was previously investigated for syncope with a 7-day electrocardiogram (ECG) tape recording, which showed sinus rhythm with 12 episodes of bradycardia in 24 hours, the longest for 27 beats, lowest rate 23 beats per minute (bpm), ventricular ectopic beats, and pauses in cardiac activity < 2.5 seconds (at random times), and no ischemic changes. The pauses occurred at random times and were not related to any physical activity or time of day. This was not investigated further.

He does not smoke tobacco; he is a social drinker. He is a retired engineer and lives with his wife in a house, completely independent in his daily activities.

On examination, his temperature was 36.9, blood pressure 170/100 mmHg, oxygen saturation 98% on room air, and respiratory rate 12. His heart rate was 54. CNS, peripheral nervous system, chest, heart, and abdominal examinations were normal. There was no chest pain.

Metabolic, infectious, cardiac, and CNS causes for syncope were considered for the differential diagnosis. His blood tests were normal (Table 1), a venous blood test was normal (not shown), and lying and standing blood pressures were 170/100 and 160/100, respectively. His heart rate was 54 bpm without orthostatic changes. Urine analysis and chest X-ray were normal, ruling out a significant infection.

Heart block, ectopic beats, and arrhythmias were investigated by ECG, which showed sinus bradycardia of 54 bpm with occasional premature ventricular complexes and no features of acute ischemic events.

Cranial causes for syncope include epilepsy, cerebrovascular accident (CVA), transient ischemic attack (TIA), space-occupying lesion, raised intracranial pressure, and trauma.

A computed tomography (CT) head scan showed a hyperdense lesion 2.8 × 1.8 cm in the left basal ganglia region, causing localized mass effect with minimal effacement of left Sylvian fissure. Our patient was admitted for further investigations. Based on CT findings, magnetic resonance imaging (MRI) was requested, which showed diffuse high signal and a mild degree of enhancement in the medial portion of the left temporal lobe extending into globus pallidus and thalamus corresponding to CT appearance. These appearances were most consistent with infiltrating the glioma. A CT scan of his chest/abdomen/pelvis was then requested to assess for other cancer lesions. It demonstrated multinodular goitre, but otherwise no obvious primary or metastatic disease.

He had a primary tumour biopsy which showed anaplastic astrocytoma: isocitrate dehydrogenase (IDH) wild type, grade III, IDH r132h negative. He was discussed with a multidisciplinary team (MDT) and was treated with 8 mg dexamethasone and radiotherapy. His ECG improved showing 74 bpm sinus rhythm with first degree AV block. He is currently asymptomatic and has no syncopal episodes.

For more details click on the link: https://doi.org/10.1186/s13256-020-2345-8