tachy brady syndrome vs sick sinus syndrome

Located in the superior right atrium, it automatically produces cyclical electrical activity to initiate each heartbeat in normal sinus rhythm. Please leave any comments you may have on Part I, below.The sinoatrial or sinus node (SAN) is the heart’s natural pacemaker. Robertson and continue to manager her progress. Continue to Part II of this case where you will identify the appropriate pacemaker for Mrs. In these instances, the goal of therapy is to establish the diagnosis with monitoring and pursue a pacemaker only if there are prolonged pauses, symptoms of bradycardia, or if rate control agents are needed. Often, the concurrence of AF and SSS in elderly patients is a contraindication for traditional therapies such as beta-blockers and calcium channel blockers. Restarting nodal agents (metoprolol or diltiazem) or choosing an antiarrhythmic would help the RVR but could worsen the sinus node dysfunction and pauses. Additional indications include sinus pause/arrest of >3 sec and pause of >5 sec while in AF. Second, the nodal agents she is taking to manage AF with RVR are contraindicated in patients with bradyarrhythmias and pauses (Class II). First, she has symptoms of lightheadedness with her pauses (Class I). The patient has multiple indications for a pacemaker. Refer to electrophysiology for a pacemaker Refer to electrophysiology for a pacemakerĪnswer: D. What is the next best step in management?ĭ. However, her episodes are now occurring more frequently with more episodes of palpitations.ģ. Robertson’s metoprolol in the hopes that it will improve her symptoms. SSS can also be aggravated by many of the medications used to manage AF (rate control agents such as metoprolol, diltiazem, digoxin).Ĭase. Underlying pathology often involves microfibrosis of the SA node. Risk factors for SSS are similar to those for AF (age, CAD, HTN, DM, valvular disease) and therefore, the two often coexist. In this case, the rapid discharge of AF can result in sinus node “fatigue” and exacerbation of bradyarrhythmias or post-conversion (to sinus rhythm) pauses. Tachy-brady syndrome is a variant of sick sinus syndrome (SSS), where there is intrinsic sinus node dysfunction that leads to alternating slow and fast heart rates. There are also some AF episodes with slow ventricular response (heart rate in the 40s) and pauses in AF of as long as 5.1 seconds.Ģ. You order a 48h holter monitor and it returns, showing multiple bursts of AF with rapid ventricular response (RVR) followed by episodes of conversion back to sinus rhythm with post-conversion pauses (longest 3.2 seconds). Finally, extended monitoring with an implantable loop recorder is only indicated when an occult arrhythmia is suspected, such as in cryptogenic stroke or unexplained recurrent syncope.Ĭase. An event monitor only autocaptures notable arrhythmias or patient-triggered events and does not provide the more comprehensive information about AF rate control recoreded by the Holter monitor. The 48h monitoring will also autocapture any tachy- or bradyarrhythmias.Ī 7d event monitor (prolonged monitoring) would be indicated if the episodes were less frequent than 72 hours (longest duration of a Holter recording). A 48h Holter monitor will not only capture the episodes but will also provide histograms of heart rate trends as well as average heart rate so that overall rate control can be assessed. Robertson needs a baseline ECG, weekly monitoring is not indicated. Weekly ECG monitoring in a patient with chronic AF is likely to provide only a “snapshot” and may not capture the acute episode.

What type of monitoring do you recommend? You are concerned about whether these represent poorly rate-controlled AF.ġ. The episodes occur 1-2 times a day and usually last for a few minutes. Recently, she has started complaining of episodes of palpitations with feelings of heart racing followed by episodes of lightheadedness. She also takes lisinopril 10 mg and metformin 500 mg BID. She has been taking dabigatran and metoprolol 50 mg twice daily. Robertson is an 85-year-old patient with a history of long-standing paroxysmal atrial fibrillation (AF). The problem comes when they co-exist and as a result, make management of each disease more challenging. Both atrial fibrillation and sick sinus syndrome (a subset of which is also known as “tachy-brady” syndrome) are more common in elderly patients.

Tachy brady syndrome vs sick sinus syndrome