From the CLINIcAL InQUiRiES Family Physicians Inquiries Network Jennifer E. DeVoe, What is the best approach MD, DPhil Department of Family Medicine, Oregon Health and Science to the evaluation of resting University, Portland Dolores Zegar Judkins, tachycardia for an adult? MLS Oregon Health and Science University Library, Portland EVIDENCE - BASED ANSWER The best evidence about the diagnostic evaluation suggests a sinus tachycardia evaluation of resting tachycardias in adults with narrow QRS complexes and no is currently outlined by practice guide- identifiable secondary cause, a 24-hour lines.1 Initial evaluation includes clinical Holter monitor is usually recommended history, physical examination, and 12-lead (strength of recommendation: C, based electrocardiogram (ECG). If the initial ® onDowden expert opinion). Health Media CLINICAL COMMENTARYCopyrightFor personal use only Wide-complex tachycardias and irregular more relaxed pace. For nonurgent cases it heartbeats should be urgently managed is important to keep in mind the differential This Clinical Inquiry organizes a rational diagnosis and rationally evaluate the likely approach to tachycardia, which is frequent- causes. In my patient population, I tend to ly an incidental and asymptomatic finding see sinus tachycardias in young healthy on patient intake. The recommendation of patients in whom no secondary cause aside evaluating a 12-lead ECG for sinus vs non- from anxiety is identified. Oftentimes I sinus tachycardia, then further investigating follow up after initiating treatment for underlying causes, helps frame the workup anxiety or its underlying cause and find in an approachable manner. Particularly that the tachycardia has resolved. In these helpful is the pointer that the wide- cases, I have been less aggressive about complex tachycardias and irregular ordering a 24-hour Holter monitor. heartbeats should be urgently managed, Laurel Woods, MD whereas the rest can be assessed at a Group Health Family Medicine Residency Program, Seattle, Wash æ Evidence Summary was an international practice guideline de- Heart rate varies by age; however, tachy- veloped by the American College of Car- cardia in adults is usually defined as a rate diology, the American Heart Association exceeding 100 beats/minute.1 Tachycardia Task Force on Practice Guidelines, and the at rest requires a diagnostic evaluation. European Society of Cardiology Commit- However, our search found no systematic tee for Practice Guidelines.1 reviews, randomized trials, or prospective This joint guideline recommends that cohort studies relevant to this question. the diagnostic evaluation of a hemody- The highest level of evidence we located namically stable patient should begin with www.jfponline.com VOL 56, NO 1 / JAnUARY 2007 59 For mass reproduction, content licensing and permissions contact Dowden Health Media. ES i R i QU n TABLE I supraventricular (from the sinus node, the Potential secondary causes of atria, and the atrioventricular junction) in AL resting sinus tachycardia5–7 c origin, and wide QRS complex tachycar- Hyperthyroidism dias are usually ventricular (from all sites below the AV junction).2,3 If an irregular CLINI Fever heartbeat or wide-complex tachycardia Sepsis is detected, appropriate management (in- Anxiety cluding possible urgent referrals) should begin immediately.1 A stable patient with Pheochromocytoma a regular rhythm and a narrow QRS com- Anemia plex can be further investigated at a more Hypotension and shock relaxed pace. Refer to the TABLe for a listing of com- Pulmonary embolism mon secondary causes for sinus tachycar- Acute coronary ischemia and myocardial infarction dia, which should direct lab investigations. Heart failure If no secondary cause is easily identifiable, a 24-hour monitor is recommended as the Chronic pulmonary disease next step. Hypoxia Exposure to medications, stimulants, or illicit drugs Recommendations from Others Malignancy Textbook chapters and other review ar- ticles regarding this topic describe a simi- Pregnancy lar initial evaluation and provide further details about interpreting the 12-lead a clinical history, physical examination ECG.2–7 The most relevant and recent with relevant labs, and 12-lead ECG.1 review article suggests that further inves- Many patients with tachycardia are tigation of narrow QRS complex tachy- FAST TRACK asymptomatic; however, common symp- cardias with a regular rate currently If a 12-lead ECG toms and complaints include palpitations, involves 4 diagnostic categories: normal fatigue, lightheadedness, chest discomfort, sinus tachycardia (ie, secondary cause suggests sinus dyspnea, presyncope, or syncope.1 If the can be identified), inappropriate sinus tachycardia patient has experienced symptoms, it is of tachycardia (IST), postural orthostatic with narrow QRS crucial importance to obtain a clinical his- tachycardia syndrome (POTS), and sinus complexes and no tory describing the pattern in terms of the node reentry tachycardia (SNRT).4 number of episodes, duration, frequency, If a secondary cause is identified, it secondary cause, mode of onset, and possible triggers.1 should be treated appropriately. If no a 24-hour The main goals of the physical ex- underlying cause is discovered, a 24-hour Holter monitor amination, labs, and the 12-lead ECG are Holter monitor is recommended. to determine if the patient has a sinus or Persistent sinus tachycardia (some- is recommended nonsinus tachycardia and to look for oth- times with nocturnal normalization of er findings that may suggest either a cause heart rate) is diagnosed as IST.4 If the for the tachycardia or any complications monitor shows paroxysmal episodes of resulting from the tachycardia. sinus tachycardia, determine if they are First, determine if the patient’s heart- triggered by orthostasis and relieved by beat is regular or irregular. Atrial flutter recumbency (confirm with head upright and atrial fibrillation are common causes tilt test) to make the diagnosis of POTS. If of an irregular heartbeat that can easily be it is not POTS, the recordings from the 24- diagnosed with a 12-lead ECG. Second, hour Holter monitor help make the diag- determine the width of the QRS interval: nosis of SNRT, which consists of sudden, narrow QRS complex tachycardias are paroxysmal, and usually nonsustained 60 VOL 56, NO 1 / JAnUARY 2007 THE JOURNAL OF FAMILY PRActIcE Evaluation of resting tachycardia in an adult p FIGURE Diagnostic algorithm for evaluating tachycardias4 HEART RATE >100 beats/minute SINUS TACHYCARDIA Non-SINUS TACHYCARDIA P waves precede QRS complexes; No clear P-QRS patterns is there an underlying cause? UNDERLYING CAUSE IDENTIFIED NO UNDERLYING CAUSE MAKE DIAGNOSIS • Diagnose as normal IDENTIFIED Initiate treatment sinus tachycardia Consider 24-hour Holter monitor • Initiate treatment Persistent or paroxysmal? PERSISTENT TACHYCARDIA PAROXYSMAL TACHYCARDIA • Diagnose with inappropriate sinus Is there a postural trigger? tachycardia (IST) (Head upright tilt test) • Initiate treatment (bradycardic agents or surgical ablation) NO POSTURAL TRIGGER POSTURAL TRIGGER • Diagnose sinus node reentry • Diagnose postural orthostatic tachycardia (SNRT) tachycardia syndrome (POTS) • Initiate termination treatments • Initiate treatment for acute episodes (pharmacologic and • Consider prevention for frequent nonpharmacologic options) episodes tachycardia.4 The FIGUre shows an algo- eds. Textbook of Primary Care Medicine. 3rd ed. rithm of one common diagnostic strategy St. Louis, Mo: Mosby; 2001:528–537. 2–7 4. Stoenescu ML, Kowey PR. Tachycardias. In: Rakel for evaluation of tachycardia. RE, ed. Conn’s Current Therapy. 57th ed. Philadel- phia, Pa: Saunders; 2005:354–355. REFERENCES 5. Olgin JE, Zipes DP. Specific arrhythmias: diagnosis and treatment. In: Braunwald E, ed. Braunwald’s 1. American College of Cardiology/American Heart Heart Disease: A Textbook of Cardiovascular Medi- Association Task Force on Practice Guidelines and cine. Philadelphia, Pa: Saunders; 2005:803–806. the European Society of Cardiology Committee for Practice Guidelines (ACC/AHA/ESC). ACC/AHA/ 6. Castellanos A, Moleiro F, Chakko S, et al. Heart rate ESC guidelines for the management of patients variability in inappropriate sinus tachycardia. Am J with surpraventricular arrythmias-executive sum- Cardiol 1998; 82:531–534. mary. J Am Coll Cardiol 2003; 42:1493–1531. 7. Krahn AD, Yee R, Klein GJ, Morillo C. Inappropri- 2. Yusuf S, Camm JA. Deciphering the sinus tachy- ate sinus tachycardia: evaluation and treatment. J cardias. Clin Cardiol 2005; 28:267–276. Cardiovasc Electrophysiol 1995; 6:1124–1128. 3. Martin DT. Arrhythmias. In: Noble J, Greene HL, www.jfponline.com VOL 56, NO 1 / JAnUARY 2007 61.