A common event of Consciousness Loss: diagnostic and therapeutic considerations

Case Report: A 60-year-old patient with hypertension and mild COPD came to the ED with a 24-hour period of unexplained discomfort and epigastric pain. Two similar events, which were quickly reversed, occurred in the last month. The patient is on pharmacological treatment at home with omeprazole, an ACE-I, a β-blocker and ASA. Vital parameters: BP=150/90, HR=62/m', T°C=36.8°C, GCS=15. EKG: normal sinus rhythm with isolated premature atrial contractions (PACs) and left ventricular hypertrophy (LVH; Lewis index ≥17). Laboratory tests: in range serum electrolytes, Hb=13.8 g/dl, Troponin is normal. During the observation period, a transient loss of consciousness (TLOC) occurred while standing: PA=140/70; no EKG changes. Discussion: TLOC is defined as a state of LOC of short duration, with amnesia for the period of unconsciousness. It includes Syncope, epileptic seizures, psychogenic forms and TLOC from rare causes (e.g., vertebrobasilar TIA). In our patient, LOC findings and clinical history are suggestive of Syncope, defined as LOC due to a fall in systemic blood pressure (BP). It is characterized by a rapid onset, short duration, and spontaneous complete recovery. We distinguish three main types: reflex, cardiovascular and orthostatic hypotension (OH) Syncope. The latter is often drug-induced, but can also result from autonomic failure (e.g., diabetes). In the diagnostic work-up of Syncope, alongside the clinical history and EKG, physical examination with supine and standing BP measurements, and laboratory tests, including dosing of D-dimer, play a central role. The onset of LOC during the upright position suggests an OH syncope; however, no decrease from baseline in systolic or diastolic BP was observed in the transition to the upright position. Since it is not possible to specify the nature of Syncope, risk stratification is necessary. According to this stratification, our patient was classified as high-risk. This detection and the LVH led us to consider Cardiac Syncope and hospitalisation. During admission, he performed an echocardiogram and bedside ECG monitoring, with PVCs and PACs recording. At discharge, ABPM is recommended: OH is frequently associated with a nocturnal non-dipping or even reverse-dipping BP pattern in autonomic failure. During 24-hour Holter monitoring, 4666 single PACs and 1538 PVCs (10 in pairs) were recorded. In the general population, frequent PVCs (presence of >30 PVCs per hour) are associated with increased cardiovascular risk. They can be observed in patients with hypertension and their prevalence rises with increase in LV mass. In our case, the ambulatory EKG recorded > 60 PVCs/h. In contrast, PAC is considered a benign EKG event. However, recent data support its association with future AF. Durmaz and co-workers have regarded PACs as frequent (fPACs) if > 30 in an hour. They also reported that patients with fPACs had more comorbidity, but also an 11-fold higher risk of new-onset AF than those without fPACs. Furthermore, patients with fPACs had a greater mean CHA2DS2-VASC score and a higher use of β-blockers. Conclusions: As a result of these observations, β-blocker was withdrawn and flecainide was introduced. This is a class Ic antiarrhythmic drug with slow kinetic, which produces its effects at all cardiac frequencies, while class Ib drugs are effective only at high heart rates. Flecainide was also preferred because it does not interfere with potassium channels, unlike class Ia and III antiarrhythmic.

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