a major teaching hospital of harvard medical school role of echocardiography in atrial fibrillation...

A major teaching hospital of Harvard Medical School

Role of Echocardiography in Atrial FibrillationRole of Echocardiography in Atrial Fibrillation

Kyle K. PondKyle K. PondDecember 15December 15thth, 2004, 2004


OutlineOutline1. Prevalence and epidemiology of atrial fibrillation1. Prevalence and epidemiology of atrial fibrillation2. Use of transthoracic echocardiography2. Use of transthoracic echocardiography

-chamber sizes and function-chamber sizes and function-valvular function-valvular function

3. Use of transesophaeal echocardiography3. Use of transesophaeal echocardiography-detection of atrial thrombi-detection of atrial thrombi-detection of other high risk factors-detection of other high risk factors-role timing of cardioversion-role timing of cardioversion-assessment of return of atrial mechanical -assessment of return of atrial mechanical

functionfunction


Atrial FibrillationAtrial FibrillationCommon arrhythmiaCommon arrhythmia

-estimated 2.3 million adults in US-estimated 2.3 million adults in US-approaching 200,000 hospital admissions/yr-approaching 200,000 hospital admissions/yr

Disease of the elderlyDisease of the elderly-4% of the population over the age of 60-4% of the population over the age of 60-5/122,000 healthy Air Force recruits found to -5/122,000 healthy Air Force recruits found to

have atrial fibrillation on screening EKG have atrial fibrillation on screening EKG (Hiss et al (Hiss et al Circulation 1962)Circulation 1962)

20-26/100,000 deaths in Massachusetts in 1999 20-26/100,000 deaths in Massachusetts in 1999 listed listed AF as contributing causeAF as contributing cause


Epidemiology (cont)Epidemiology (cont)Atrial Fibrillation is BADAtrial Fibrillation is BAD

-Data from the FHS suggests that chronic AF -Data from the FHS suggests that chronic AF confers an almost 2X increase in both overall and confers an almost 2X increase in both overall and cardiovascular mortality (women>men). cardiovascular mortality (women>men). (Vaziri et al, Circ (Vaziri et al, Circ 1994).1994).


My algorithm for treating atrial fibrillation


Potential Clinical ConsequencesPotential Clinical Consequences1. Thromboembolism1. Thromboembolism2. Tachycardia mediated cardiomyopathy2. Tachycardia mediated cardiomyopathy3. Hemodynamic deterioration3. Hemodynamic deterioration4. Symptoms4. Symptoms


Role of TTE in atrial fibrillationRole of TTE in atrial fibrillation-Provides useful/prognostic information -Provides useful/prognostic information

about cardiac anatomy, structure, and functionabout cardiac anatomy, structure, and function


Left AtriumLeft Atrium-normal is <4.0cm -normal is <4.0cm -size of left atrium is important in helping to determine -size of left atrium is important in helping to determine

prognosisprognosis-increased size decreases the probability of maintaining -increased size decreases the probability of maintaining

sinus rhythm sinus rhythm -increased LA size among the strongest predictors -increased LA size among the strongest predictors of development of new AF (HR 1.39 in previously of development of new AF (HR 1.39 in previously mentioned FHS paper)mentioned FHS paper)

-chronic AF, rheumatic MV dz, and severe LA -chronic AF, rheumatic MV dz, and severe LA enlargement (>6cm) have highest risk of recurrence (9)enlargement (>6cm) have highest risk of recurrence (9)

-ACC/AHA guidelines for anticoagulation in severe -ACC/AHA guidelines for anticoagulation in severe rheumatic MS in absence of AF-> LA size > 5.5 cmrheumatic MS in absence of AF-> LA size > 5.5 cm


(cont)(cont)--LA size increases with progressive duration of AFLA size increases with progressive duration of AF

-suggests AF “promotes” LAE-suggests AF “promotes” LAE-DCCV and maintenance of sinus rhythm are thought to -DCCV and maintenance of sinus rhythm are thought to possibly reverse LAE possibly reverse LAE


SummarySummary-Evaluation of the LA size provides important -Evaluation of the LA size provides important prognostic information prognostic information

-ability to maintain sinus rhythm-ability to maintain sinus rhythm-likelihood of recurrence of AF or initial -likelihood of recurrence of AF or initial

development of AF in someone without a development of AF in someone without a prior hxprior hx-presence of significant LAE should not be an exclusion -presence of significant LAE should not be an exclusion criteria for CV criteria for CV


Left VentricleLeft Ventricle--LVH, focal WMA, AS, pericarditis, or other causes of AFLVH, focal WMA, AS, pericarditis, or other causes of AF-LV dysfunction independently predicts stroke risk-LV dysfunction independently predicts stroke risk

-based on meta-analysis of 1066 patients-based on meta-analysis of 1066 patients-in control groups-incidence of CVA -in control groups-incidence of CVA

-9.3%/yr in patients with mod/severe LV dysfxn-9.3%/yr in patients with mod/severe LV dysfxn-4.4%/yr in patients with no/mild LV dysfxn -4.4%/yr in patients with no/mild LV dysfxn


Mitral ValveMitral ValveTTE evaluates the degree of mitral valve diseaseTTE evaluates the degree of mitral valve disease

-Gives prognostic information-Gives prognostic information -Pts can initially present in afib,->can detect mitral -Pts can initially present in afib,->can detect mitral stenosis stenosis

-can affect duration of tx-can affect duration of tx


Mitral RegurgitationMitral Regurgitation--evaluated by TTEevaluated by TTE-? protective against atrial fibrillation due to -? protective against atrial fibrillation due to

minimization of stasis in the LA and appendage minimization of stasis in the LA and appendage Goldsmith et al, Goldsmith et al, AJC 2000)AJC 2000)


TTE can help risk-stratify patients with atrial TTE can help risk-stratify patients with atrial fibrillationfibrillation--specifically low risk clinical patients may be at increased risk specifically low risk clinical patients may be at increased risk when TTE performed when TTE performed -SPAF data-SPAF data

-low clinical, low echocardiographic risk (<1%/yr CVA)-low clinical, low echocardiographic risk (<1%/yr CVA)-low clinical, high echocardiographic risk (>5%/yr CVA)-low clinical, high echocardiographic risk (>5%/yr CVA)


Bottom line: “The routine performance of Bottom line: “The routine performance of transthoracic echocardiography is suggested transthoracic echocardiography is suggested for all patients presenting with their first for all patients presenting with their first episode of AF to obtain information regarding episode of AF to obtain information regarding cardiac structure and function.” cardiac structure and function.”

-WJM “UpToDate--2/04”-WJM “UpToDate--2/04”


Left Atrial ThrombiLeft Atrial Thrombi--In general poorly visualized by TTE (39-63% sensitive)In general poorly visualized by TTE (39-63% sensitive)

-lower in LAA (<20% visualization of LAA on TTE).-lower in LAA (<20% visualization of LAA on TTE).-TEE much better -TEE much better

->200 patients prior to MV repair/replacement->200 patients prior to MV repair/replacement-56% with H/O afib-56% with H/O afib

-sensitivity/specificity for left atrial thrombi were -sensitivity/specificity for left atrial thrombi were 100%/99% as compared with direct surgical visualization 100%/99% as compared with direct surgical visualization ((Manning WJ et al, Arch Int Med 1995)Manning WJ et al, Arch Int Med 1995)


LA thrombi in AFLA thrombi in AF-seen in 10-15% of pts. with >72 hours of AF-seen in 10-15% of pts. with >72 hours of AF--much higher in pts with higher risk features --much higher in pts with higher risk features --more likely if any of the following are visualized--more likely if any of the following are visualized

-dense LA smoke-dense LA smoke-low LAA velocity (usually <20cm/sec)-low LAA velocity (usually <20cm/sec)-complex aortic plaque -complex aortic plaque

(SPAF-III TEE substudy)(SPAF-III TEE substudy)


TEE for identifing LA thrombus in AFTEE for identifing LA thrombus in AF-facilitated early cardioversion-facilitated early cardioversion-in patients with acute thromboembolism (TE) -in patients with acute thromboembolism (TE)

-->40% of patients with acute TE and newly >40% of patients with acute TE and newly recognized AF were found to have LA thrombusrecognized AF were found to have LA thrombus-Routine TEE in this population is controversial at -Routine TEE in this population is controversial at bestbest


TEE for facilitated early TEE for facilitated early cardioversioncardioversion-cardioversion->improves -cardioversion->improves symptoms, cardiac symptoms, cardiac function, function, ? decrease the risk of ? decrease the risk of thrombus formationthrombus formation-DCCV without antecedent -DCCV without antecedent anticoagulationanticoagulation

-approx 6% -approx 6% incidence of clinical TEincidence of clinical TE


Transesophageal Echocardiographically Facilitated Early Transesophageal Echocardiographically Facilitated Early Cardioversion From Atrial Fibrillation Using Short-Term Cardioversion From Atrial Fibrillation Using Short-Term Anticoagulation (Manning WJ et al, JACC 1995)Anticoagulation (Manning WJ et al, JACC 1995)

-230 consecutive patients with atrial fibrillation >2 days or -230 consecutive patients with atrial fibrillation >2 days or unknown durationunknown duration

-all underwent TEE-identifying 40 atrial thrombi in 34 patients -all underwent TEE-identifying 40 atrial thrombi in 34 patients (15%).(15%).

-186/196 (95%) without thrombi had successful DCCV to NSR—-186/196 (95%) without thrombi had successful DCCV to NSR—none had a thromboembolic eventnone had a thromboembolic event

Bottom Line-1Bottom Line-1stst large scale study to show that TEE facilitated early large scale study to show that TEE facilitated early cardioversion with short-term anticoagulation is safe and effective.cardioversion with short-term anticoagulation is safe and effective.


AF of <48 hours durationAF of <48 hours duration-appears to be little role for TEE-appears to be little role for TEE

-375 patients with AF < 48 hours duration; no TEE-375 patients with AF < 48 hours duration; no TEE-conversion to NSR in 95%-conversion to NSR in 95%

-clinical thromboembolic event in 3 (0.8%)-clinical thromboembolic event in 3 (0.8%)-similar to rate when on coumadin X 4 weeks-similar to rate when on coumadin X 4 weeks


Left Atrial Appendage FunctionLeft Atrial Appendage Function- blood flow velocity is a quantifiable measure of stasis- blood flow velocity is a quantifiable measure of stasis- low velocity associated with higher risk of thrombus - low velocity associated with higher risk of thrombus formationformation- also associated with dense spontaneous echo - also associated with dense spontaneous echo contrastcontrast- low blood flow velocity (<15mm/sec) associated with - low blood flow velocity (<15mm/sec) associated with increased risk of CVA increased risk of CVA (Shivelly BK, et al JACC 1996; 27:1772)(Shivelly BK, et al JACC 1996; 27:1772)


Velocity predicts long term maintenance of sinus Velocity predicts long term maintenance of sinus rhythm in pts with nonvalvular AF rhythm in pts with nonvalvular AF (Antonielle E, JACC (Antonielle E, JACC 2002:39)2002:39)

-186 pts eventually successfully cardioverted to -186 pts eventually successfully cardioverted to NSR. All had AF>48 hours.NSR. All had AF>48 hours.

-TEE/TTE/clinical parameters obtained-TEE/TTE/clinical parameters obtained-at one year F/U 91/186 patients were in NSR-at one year F/U 91/186 patients were in NSR


Normal Doppler flow pattern in the left atrial appendage. There is appendage emptying following the P

wave and appendage filling following the QRS.


Spontaneous Echo ContrastSpontaneous Echo Contrast-can be seen on TTE or more commonly TEE-can be seen on TTE or more commonly TEE-“likely due to blood stasis in a cavity or related to -“likely due to blood stasis in a cavity or related to

alterations in blood components such as RBCs, fibrinogen, alterations in blood components such as RBCs, fibrinogen, or platelets” (Manning WJ in Otto).or platelets” (Manning WJ in Otto).

-Fc receptor on platelet binding to fibrinogen-Fc receptor on platelet binding to fibrinogen-spontaneous contrast increases likelihood of LAA clot -spontaneous contrast increases likelihood of LAA clot

(Black et al JACC 1991)(Black et al JACC 1991)

-spontaneous contrast increases likelihood of CVA-spontaneous contrast increases likelihood of CVA(Chimowitz MI et al 1993)(Chimowitz MI et al 1993)

--not a “treatable” finding->marker for increased risk not a “treatable” finding->marker for increased risk -coumadin and ASA have no effect on smoke-coumadin and ASA have no effect on smoke-does reduce risk of CVA -does reduce risk of CVA


Is the presence of spontaneous echo contrast Is the presence of spontaneous echo contrast in the absence of LAA thrombus a in the absence of LAA thrombus a contraindication (relative or otherwise) for contraindication (relative or otherwise) for subsequent DCCV?subsequent DCCV?


Return of Atrial Mechanical FunctionReturn of Atrial Mechanical Function--Pulsed doppler transmitral echo can assess LA functionPulsed doppler transmitral echo can assess LA function-DCCV of AF of short duration leads to earlier return of -DCCV of AF of short duration leads to earlier return of

atrial fxnatrial fxn-Longer duration AF takes longer for atrial function to -Longer duration AF takes longer for atrial function to

recover recover -Led to recommendation of longer term anticoagulation -Led to recommendation of longer term anticoagulation

post-DCCVpost-DCCV-clinical utility unclear-clinical utility unclear


Other controversies/future questions Other controversies/future questions 1. TEE before DCCV in patients with prior TEE evidence 1. TEE before DCCV in patients with prior TEE evidence

of thrombus and then subsequent adequate anticoagulationof thrombus and then subsequent adequate anticoagulation2. Better why to risk stratify patients to ASA or coumadin 2. Better why to risk stratify patients to ASA or coumadin

based on TEE findings based on TEE findings 3. Is DCCV worse for the LA than pharmacologic 3. Is DCCV worse for the LA than pharmacologic

cardioversion?cardioversion?

a major teaching hospital of harvard medical school role of echocardiography in atrial fibrillation...

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