Question: An 82-year-old patient comes to the clinic due to sudden and frequent dizziness, without prodromes, of short duration and that subside spontaneously, without ever presenting syncope. The physical examination and the baseline electrocardiogram are normal. In an ambulatory record of the electrocardiogram during 24 hours, short duration phases of absence of P waves before the QRS are detected with an escape rhythm of the atrio-ventricular junction with narrow QRS at 40 bpm and a wave at the beginning of the ST segment corresponding to a retrograde P. No periods of asystole greater than 3 seconds are detected. Before this you would say: 
 Options:  <1> The patient has an atrioventricular block of 3rd degree and requires the implantation of a pacemaker. <2> The absence of periods of asystole> 3 seconds excludes a cardiac cause of dizziness. <3> A pharmacological treatment that would increase conduction in the atrio-ventricular node would be indicated. <4> The patient presents a sinus dysfunction with sinoatrial block and requires implantation of a pacemaker due to the presence of symptoms. <5> The alterations detected in the ambulatory electrocardiogram are typical of patients of this age and there is no indication of therapeutic intervention.
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