Vertigo/Atrial Fibrillation

Highlights from the College of Family Physicians of Canada’s Family Medicine Forum, 2009

Educational Objectives

The goal of this program is to improve management of vertigo and atrial fibrillation (AF). After hearing and assimi­lating this program, the clinician will be better able to:

1.   Distinguish among different conditions that cause dizziness, based on patient history and clinical findings.

2.   Describe the management of benign paroxysmal positional vertigo and endolymphatic hydrops.

3.   Discuss dizziness associated with head trauma.

4.   Review data about the efficacy and safety of rhythm control and rate control drugs for AF.

5.   Select appropriate therapy to reduce risk for stroke or thromboembolism in patients with AF.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of in­terest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the following has been disclosed: Dr. Gillis is a consultant for Medtronic, and has received speaker honoraria and fellowship support from Medtronic and St. Jude Medical. In her lecture, Dr. Gillis presents information that is related to the off-label or investigational use of a therapy, product, or device. Dr. Lange and the planning committee reported nothing to disclose.

Acknowledgments

Drs. Lange and Gillis spoke in Calgary, AB, at Family Medicine Forum 2009, presented October 29-31, 2009, by the College of Family Physicians of Canada. The Audio-Digest Foundation thanks the speakers and the College of Fam­ily Physicians of Canada for their cooperation in the production of this program.

Vertigo

Beth Lange, MD, Otolaryngologist and Neuro-otologist, Alberta Health Care Services, Calgary, AB

Vestibular system: most patients with peripheral vestibular dysfunction recover because 1) central nervous system (CNS) resets incorrect information received from ears by weighing it against information received from eyes, and; 2) proprioceptive areas in feet and ankles maintain balance; assess eyes; in elderly, check vibration sense, re­flexes, and position sense in toes

Vertigo: illusion of movement where none exists; implies asymmetry between right and left; does not always imply peripheral vestibular dysfunction; 60% of patients destined for stroke may complain of dizziness (not necessarily vertigo); vertigo often prominent in cardiac dysfunction

Oscillopsia: seen in ototoxicity and in patients on chemotherapy; patients complain of blurred vision; patients on oto­toxic medications (eg, 24-hr gentamicin) should be assessed; testing  —  ototoxicity possibly developing if moving head while looking at large printed word produces movement or blurring of word

Evaluation of dizziness: problematic to make diagnosis on patient history alone; speaker gives patients 3-page ques­tionnaire about symptoms before seeing them; patients (especially elderly) have difficulty describing symptoms; patients may not mention other symptoms when overwhelmed by dizziness and vomiting; ask about headache, tin­gling around mouth, dysarthria, and imbalance; severe problems usually present with nausea, vomiting, and imbal­ance; assess reduced hearing; clinical signs more re-cognizable in patients with true disability; ask about bothersome movements; if symptoms worsen only when patient gets up, consider postural problem

Types of dizziness: true positional  —  occurs when patients lie down, roll to one side, and rise (or with hyperextension of head); movement-induced  —  occurs with all types of movement; sometimes confused with positional dizziness; ask whether dizziness occurs only while walking (consider cerebellar problem; peripheral vestibular system stimu­lated with all movements, even while driving); exercise-induced  —consider cardiac problem, lack of physical con­ditioning, or spinocerebellar ataxia type 6 abnormality (associated with familial hemiplegia syndromes); if dizziness induced by arm movement (eg, weight-lifting), listen at base of neck for bruit (suggests subclavian steal syndrome); visually-induced  —  common in migraineurs; may present as new symptom in patients developing mul­tiple sclerosis

Physical examination: review questionnaire; ask about initial episode and current symptoms; test rapid alternating movements and corneal reflex; identifying nystagmus  —  difficult; enlarging patient’s eyes with high-powered reading glasses may be helpful; dim lights and look at retina for »1 min, then look for movement in blood vessel in other eye; peripheral vestibular nystagmus may be seen in center gaze (accentuated by looking in direction of past component; no accentuation in central vestibular nystagmus); Fukuda stepping test for balance  —  positive if patient moves to side while stepping in place with eyes closed; hearing test  —  distract one ear by rubbing, and speak into other ear, “Suzy eats tomatoes” (start at low pitch and gradually increase); test both ears

Vestibular neuritis: common; often occurs after upper respiratory infection (URI), herpes infection, or gastrointesti­nal viral infection; patients severely ill, and always have nystagmus; treatment  —  in emergency department (ED), give dexamethasone (eg, Decadron); in office, give prednisone (1 mg/kg per day); starting steroids early may help patients recover sooner (eg, within 2 mo; most patients recover within 1 yr)

Exercise and physiotherapy: initiate after vomiting resolves; Cawthorne-Cooksey exercises involve eye and head movements and tilting; balance exercises with tossing balls challenge brain for faster recovery

Labyrinthitis: dizziness with or without hearing loss; no history of URI or worrisome CNS symptoms; presents with otologic symptoms; often confused with vestibular neuritis; if patient has history of ear infections (particularly sup­purative) and nystagmus, consider meningitis and brain abscess (important in immunosuppressed patients)

Benign paroxysmal positional vertigo (BPPV): movement in plane of semicircular canal (eg, lying back, sitting up, or rolling over) results in burst of rotary nystagmus; check for latency (ie, 1-30 sec after patient lies down); when patient lies down, brief burst of nystagmus slows down and stops, but occurs (then reverses) when patient sits up again; when patient lies down again, nystagmus improves or resolves; in patients who do not have classic rotary nystagmus, alcohol use most common cause of positional dizziness; Epley maneuver  —patient sits on side of bed, lies down quickly to one side, looks over shoulder, then sits up and lies down on other side and looks over shoulder (should be initially performed »5 times per side; dimenhydrinate [eg, Gravol] 30 min before exercise helpful); most patients with uncomplicated BPPV improve within days to weeks; difficult for patients with cervicospinal prob­lems (not recommended for elderly; associated with high recurrence of dizziness)

Endolymphatic hydrops: Meniere’s disease; classic episode  —plugged ears; roaring tinnitus; severe vertigo; lasts 6 to 8 hr; vomiting; ataxia; hearing decreases with each successive episode; rare; ask about headache and visual sen­sitivity; vertigo and hearing loss in elderly patient more likely ischemic problem than true hydrops; counsel patients about decreasing caffeine, salt, and sugar intake; treatment  —  sublingual lorazepam (eg, Ativan) for severe episodes (effective in 15-30 min; transdermal scopolamine patch slower); rectal  dimenhydrinate; diuretic (eg, acetazolamide [eg, Diamox]) for pressure symptoms (discuss contraindications); meclizine (eg, Bonine); flunarizine (Sibelium) helpful when uncertain whether dizziness related to migraine or peripheral vestibular problem; Meniett device de­creases endolymphatic pressure (if ineffective, ablative procedure required); differential diagnosis  —  atypical mi­graine; ischemic disease; autoimmune disease (consider steroid trial in patients with eg, Crohn’s disease or lupus and fluctuating hearing loss)

Ophthalmic migraine: may present as visual symptoms and dizziness without headache; few patients have classic basilar migraine (ie, migraine associated with dysarthria, visual symptoms, and bilateral hearing loss); migraine vestibulopathy diagnosis of exclusion; if dizziness clearly associated with migraine, try empiric medication (eg, flunarizine or topiramate [Topamax]; if patient not sleeping well, consider nortriptyline)

Elderly: rarely present with primary ear problem; sudden dizziness may be due to ischemic cause; perform computed tomography (CT) for patients in ED with risk factors or >60 yr of age

Trauma: short-term memory loss, headache, and loss of sense of smell likely due to central concussion; slight hear­ing loss and dizziness with movement of head can be due to whiplash, or central or vestibular concussion; distin­guishing central from peripheral concussion  —  dizziness with head movement can be sign of either, but dizziness without head movement more likely vestibular; BPPV  —  may present later if head trauma significant (ask, “is this the same kind of dizziness that you had after your accident?”); perilymph fistula  —  classic history includes dizzi­ness with straining; patient may develop plugged ears and hearing loss, especially after exertion (eg, weight-lifting) or head trauma; improves in most patients if heavy lifting and straining avoided (fistula may be repaired if hearing continues to drop)

Ototoxicity: associated with use of aminoglycosides; reassess need for ototoxic medication every week; inform pa­tients about possible dizziness and imbalance, and document

Other causes of dizziness: obstructive sleep apnea (OSA); depression; rule out nystagmus before attributing hyper­ventilation dizziness to anxiety; vestibular physiotherapy may be helpful in anxious patients

Atrial Fibrillation

Anne M. Gillis, MD, Professor of Medicine, University of Calgary, Faculty of Medicine, Calgary, AB

Complications associated with permanent atrial fibrillation (AF): increased risk for stroke, systemic thromboem­bolism, and death; mortality function of underlying structural heart disease or other comorbidities (survival in pa­tients with lone AF same as that in otherwise healthy age-matched controls)

Evaluation: history  — control of   hypertension important; OSA; look for reversible causes (eg, hyperthyroidism, pneumonia); medical history; 12-lead electrocardiography (ECG) required; echocardiography recommended

Patterns of AF: second episode of AF may occur years after first; important when considering long-term or tempo­rary antiarrhythmic drug therapy; management of persistent AF may differ from that of paroxysmal AF

Rhythm control vs rate control: trial found rhythm control not superior to rate control for reducing mortality (sur­vival curves similar); in Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, lower survival rates seen in patients randomized to rhythm control; no difference in incidence of stroke over time between patients randomized to rate control vs rhythm control; Canadian Cardiovascular Society guidelines  —  rate or rhythm control acceptable; management must be based on symptoms, patient’s preference, and risk factors (rhythm control might be favorable in high-risk groups); factors that may favor rate control include persistent AF, frequent recurrent AF, less symptomatology, older age, and hypertension; according to Atrial Fibrillation and Congestive Heart Failure (AF-CHF) study, rhythm control appears more beneficial than rate control in HF

Treatment of newly diagnosed AF: paroxysmal AF  — consider anticoagulation; treat if symptomatic, or if ventricu­lar rate uncontrolled; persistent AF  —  restore sinus rhythm with electrical or pharmacologic cardioversion; tempo­rary use of antiarrhythmic drugs (consider maintenance and long-term use); permanent AF  —  anticoagulation and rate control drugs as required; rhythm control  —  may need to consider cardioversion; reevaluate therapy over time (as AF evolves, antiarrhythmic drugs may no longer maintain sinus rhythm)

Infrequent episodes of paroxysmal AF: “pill in the pocket” approach  —  give loading dose of propafenone (450 or 600 mg), then wait 30 min for conversion; usually prescribed with rate control drugs; shown highly effective

Medications: b-blockers; calcium channel blockers; dose based on symptoms; digoxin alone usually not effective in controlling heart rate during AF, but may be synergistic with other drugs; flecainide, propafenone, sotalol, and ami­odarone used in patients with no underlying structural heart disease; dronedarone  —  amiodarone analogue with fewer associated side effects (eg, no corneal deposits, lower frequency of hyper- or hypothyroidism, no pulmonary toxicity); shown superior to placebo

Stroke and systemic thromboembolism: moderate-risk group  —  >75 yr of age with hypertension, some left ventric­ular dysfunction, HF, or diabetes; high-risk group  —history of stroke, transient ischemic attack (TIA), or valvular heart disease; aspirin shown to slightly reduce risk for stroke in high-risk group, and warfarin significantly re­duced risk for stroke (warfarin appears superior to aspirin in all risk groups, but less beneficial because relative risk for stroke in low-risk group “very low”)

CHADS₂ score: 1 point assigned for history of CHF, hypertension, older age, or diabetes, and 2 points assigned for history of stroke or TIA; paroxysmal AF, persistent AF, and atrial flutter assigned same number of points; recommendations  —treat with aspirin (or no medication) with score of 0; treat with aspirin or warfarin (based on patient’s preference) with score of 1; treat with warfarin and maintain international normalized ratio (INR) at 2 to 3 with score ³2; CHADS₂ score and risk for stroke may vary

Other risk factors: risk for stroke associated with paroxysmal AF appears lower in recent clinical trials than in ear­lier studies; patients who have episodes of AF lasting >24 hr have higher risk for thromboembolism than those with episodes lasting <24 hr

Warfarin use in AFFIRM trial: warfarin stopped in patients prescribed antiarrhythmic drug therapy in mistaken be­lief patients would remain in sinus rhythm; risk for ischemic stroke slightly higher in patients treated with rhythm control who discontinued warfarin; maintain INR of 2 to 3 (>3 increases risk for significant hemorrhage)

Risk for intracranial bleeding in elderly: predictors  —inadequate education about use of oral anticoagulants; poly­pharmacy; INR outside of therapeutic range; study did not see association between cognitive, visual, or hearing im­pairment and increased risk of bleeding; careful use of anticoagulation can be successful; warfarin more effective than aspirin at preventing thromboembolism in elderly patients with AF, but associated with increased risk of bleeding; substantial risk in first year after initiation of anticoagulation (intense monitoring required); risk higher in patients with higher CHADS₂ scores

Cardioversion: associated with increased risk for stroke; anticoagulation recommended for 3 to 4 wk before initiat­ing and for ³1 mo after cardioversion; if AF has persisted for >48 hr, perform transesophageal echocardiography to rule out clotting in atrium, then proceed with cardioversion

Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events (ACTIVE) studies: AC­TIVE W  —  warfarin superior to clopidogrel and aspirin in preventing stroke (risk of bleeding similar); patients naive to warfarin at time of randomization and treated with either clopidogrel and aspirin had increased risk of bleeding, compared to patients who were not naive to warfarin before randomization (suggests that patients with history of bleeding on warfarin had been weeded out of group); ACTIVE A  —  minor benefit in stroke reduction with aspirin and clopidogrel (compared to aspirin alone), but risk of bleeding same as with warfarin

Principles of antithrombotic therapy: individualize therapy; reassess risk factors over time; risk stratify when de­ciding to use aspirin or warfarin

Randomized Evaluation of Long-term anticoagulation therapY (RE-LY) trial: prevention of stroke or thromboembolism  —  low-dose dabigatran equivalent to warfarin; high-dose dabigatran superior to warfarin; risk of bleeding  —  lower with low-dose dabigatran than with warfarin; equivalent in high-dose dabigatran and warfarin

Who to refer: most patients with AF; patients <35 yr of age with symptomatic AF or atrial flutter should be evalu­ated for supraventricular or atrial tachycardia (can be cured with catheter ablation); patients who remain highly symptomatic despite trials of antiarrhythmic drug therapy; patients intolerant of therapies

Suggested Reading

ACTIVE Writing Group of the ACTIVE Investigators: Clopidogrel plus aspirin versus oral anticoagulation for atrial fibrillation in the Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events (ACTIVE W): a randomised controlled trial. Lancet 367:1903, 2006; Agarwal S et al: Predictors of warfarin use in atrial fibrillation patients in the inpatient setting. Am J Cardiovasc Drugs 10:37, 2010; Black FO et al: Vestibular ototoxicity. Clinical considerations. Otolaryngol Clin North Am 26:713, 1993; Brandt T et al: Long-term course and relapses of vestibular and balance disorders. Restor Neurol Neurosci 28:69, 2010; Bron­stein AM et al: Management of the patient with chronic dizziness. Restor Neurol Neurosci 28:83, 2010; Bronstein AM: Vision and vertigo: some visual aspects of vestibular disorders. J Neurol 251:381, 2004; Connolly SJ et al: Dabigatran versus warfarin in pa­tients with atrial fibrillation. N Engl J Med 361:1139, 2009; Devaiah AK et al: Postmaneuver restrictions in benign paroxysmal posi­tional vertigo: an individual patient data meta-analysis. Otolaryngol Head Neck Surg 142:155, 2010; Fauchier L et al: Mortality in patients with atrial fibrillation and heart failure. J Am Coll Cardiol 55:168, 2010; Hain TC et al: Pharmacological treatment of ver­tigo. CNS Drugs 17:85, 2003; Halmagyi GM et al: Vestibular function after acute vestibular neuritis. Restor Neurol Neurosci 28:37, 2010; Roy D et al: Rhythm control versus rate control for atrial fibrillation and heart failure. N Engl J Med 358:2667, 2008; Rucker JC: Pearls: Nystagmus. Semin Neurol 30:51, 2010.