Echocardiography for the Electrophysiologist: Day-to-day practice Emmanuel Fares, MD EP and pacing service, Department of Cardiovascular Medicine, Cairo University Agenda Role of echo in arrhythmia management: Atrial Fibrillation: Evaluation of LA size Assessment of LV diastolic function Risk stratification (LAA thrombi detection) Role of intracardiac echo Ventricular arrhythmias and SCD: Ischemic Cardiomyopathy Non-ischemic cardiomyopathy Inheritable arrhythmogenic diseases: HCM, ARVD Role of echo in CRT optimization 1
Introduction In the setting of arrhythmias, the utility of echocardiography lies primarily in the identification of associated heart disease, the knowledge of which will influence treatment of the arrhythmia or provide prognostic information Atrial Fibrillation AF is the most frequently encountered arrhythmia in clinical practice, with an overall prevalence of 0.4% in the general population. 2
AF complications Go AS, Mozaffarian D, Roger VL, et al. Heart disease and stroke statistics 2014 update: a report from the American Heart Association. Circulation. 2014;129(3):e28-e292. Assessment of LA dimensions Left atrial dimensions: AP, transverse and longitudinal 3
Assessment of LA volume Measurement of left atrial volume from biplane method of disks (modified Simpson s rule) using apical 4-chamber (a) and apical 2-chamber (b) views at ventricular endsystole (maximum volume) Reference ranges for LA size Women Men Reference range Mildly abnormal Moderately abnormal Severely abnormal Reference range Mildly abnormal Moderately abnormal Severely abnormal Atrial dimensions LA diameter, cm 2.7 3.8 3.9 4.2 4.3 4.6 4.7 3.0 4.0 4.1 4.6 4.7 5.2 5.2 Atrial volumes LA volume/bs A, ml/m 2 22 ± 6 29 33 34 39 40 22 ± 6 29 33 34 39 40 BSA, Body surface area; LA, left atrial 4
Clinical perspectives LA size has been established as a prognostic marker for cardiovascular events: According to the data from the Framingham study, a 5-mm increase in LA dimension was associated with a 39% increased risk for development of AF. Subjects in sinus rhythm with a LA dimension over 5.0 cm had about 4X the risk of developing AF during the following period of surveillance. LA enlargement is associated with a low probability of successful cardioversion for chronic AF or maintenance of sinus rhythm An increased LA volume index can predict recurrence of AF after PVI Although AF promotes further LA enlargement, cardioversion and maintenance of sinus rhythm may reverse this process. Kaplan Meier survival curves free of new-onset atrial fibrillation. Patients are stratified according to left atrial (LA) diameter (A), LA volume (B) Philippe Debonnaire et al. Circ Arrhythm Electrophysiol. 2017;10:e004052 5
Association between left atrial size and the incidence of AF in the Cardiovascular Health Study. LAD indicates left atrial dimension; RR, relative risk. Agenda Role of echo in arrhythmia management: Atrial Fibrillation: Evaluation of LA size Assessment of LV diastolic function Risk stratification (LAA thrombi detection) Role of intracardiac echo Ventricular arrhythmias and SCD: Ischemic Cardiomyopathy Non-ischemic cardiomyopathy Inheritable arrhythmogenic diseases: HCM, ARVD Role of echo in CRT optimization 6
Assessment of LV Diastolic Function The evaluation of diastolic function in patients with AF has remained a clinical challenge: The impairment of the LA mechanical function The variable cycle lengths All echocardiographic parameters, should be measured and averaged from 5 to 10 cardiac cycles PWD study of transmitral inflow Arrow indicates early transmitral flow deceleration time (DT). E represents peak LV early diastolic filling velocity. Peak E velocity and DT vary depending on cardiac cycle length. 7
TDI Tissue Doppler imaging of the septal mitral annular velocities (e') Color M-mode Mitral inflow propagation velocity, is acquired from the apical 4-chamber view by placing a cursor over the center of mitral inflow and reducing the Nyquist limit for flow toward apex to a point when the central color turns blue. 8
Assessment of the diastolic function PWD: Mitral DT 100 ms predicted a mean of pulmonary capillary wedge pressure (PCWP) 18 mmhg TDI: E/e' (septal) > 15 and E/e' (lateral) > 10 have been shown to be highly specific for elevated LV filling pressure Color M-mode: A Vp < 45 cm/s is consistent with the presence of diastolic dysfunction Agenda Role of echo in arrhythmia management: Atrial Fibrillation: Evaluation of LA size Assessment of LV diastolic function Risk stratification (LAA thrombi detection) Role of intracardiac echo Ventricular arrhythmias and SCD: Ischemic Cardiomyopathy Non-ischemic cardiomyopathy Inheritable arrhythmogenic diseases: HCM, ARVD Role of echo in CRT optimization 9
Detection of LA thrombi TEE provides excellent visualization of posterior cardiac structures and is the modality of choice for detecting LA or LAA thrombi with a sensitivity and specificity of approximately 95% to 100% Thrombus (arrow) within the left atrial appendage 10
Spontaneous echo contrast (*) swirling detected by transesophageal echocardiography in a patient with AF It is difficult to distinguish small thrombi from artifacts, including prominent trabecular structures, duplication artifacts, coumadin ridge 11
Echocardiographic predictors of systemic thromboembolism TEE-guided early cardioversion 12
Advantages and disadvantages of TEE-guided early cardioversion Agenda Role of echo in arrhythmia management: Atrial Fibrillation: Evaluation of LA size Assessment of LV diastolic function Risk stratification (LAA thrombi detection) Role of intracardiac echo Ventricular arrhythmias and SCD: Ischemic Cardiomyopathy Non-ischemic cardiomyopathy Inheritable arrhythmogenic diseases: HCM, ARVD Role of echo in CRT optimization 13
ICE during PVE Two-dimensional ICE image that shows the Brockenbrough-curve needle is advanced from the right atrium (RA) to the fossa ovalis (FO) for transseptal puncture guided by ICE ICE advantages Detect anatomical variations of interatrial septum such as aneurismal septum, double membrane septum, PFO The use of ICE helps in determining the exact position of tip of the transseptal sheath by looking for tenting of the interatrial septum. It enables avoidance of the life-threatening complication, such as perforation of lateral wall of LA or aortic root. 14
ICE advanatges ICE is useful as a monitoring tool for titration of energy power and duration. It can control lesion formation The appearance of microbubbles resulting from overheating can precede increased impedance Ablation needs to be terminated immediately if a sudden appearance of microbubbles is observed. This can prevent tissue damage and scar formation which may promote PV stenosis, LA perforation, or pericardial effusion Agenda Role of echo in arrhythmia management: Atrial Fibrillation: Evaluation of LA size Assessment of LV diastolic function Risk stratification (LAA thrombi detection) Role of intracardiac echo Ventricular arrhythmias and SCD: Ischemic Cardiomyopathy Non-ischemic cardiomyopathy Inheritable arrhythmogenic diseases: HCM, ARVD Role of echo in CRT optimization 15
Role of echo in prediction of SCD Echocardiography remains the imaging technique of first choice to rule out the presence of structural heart disease and assess ventricular functions LVEF has consistently shown an association with increased risk of ventricular arrhythmias and therefore, this variable is included in the recommendations for ICD as primary prevention (class I) New echo indices may be associated with increased arrhythmogenicity ICD trials in heart failure EF < 35% is an indication for 1ry prevention ICD 16
Echocardiographic parameters (beyond LVEF) associated with ventricular arrhythmias in ischemic heart failure patients Imaging technique Parameter Evidence Echocardiography Speckle tracking LV GLS Reduced magnitude of LV GLS was associated with 1.24-fold increased risk of ventricular arrhythmias (95% CI 1.10 to 1.40; P = 0.0004) in 988 patients with acute STEMI LV mechanical dispersion Each 10 ms increase in LV mechanical dispersion has been associated with increased risk of arrhythmias (HR 1.7) Dobutamine stress echocardiography Inducible ischemia The presence of inducible ischemia was associated with ventricular arrhythmias (HR 2.1, 95% CI 1.2 3.5; P < 0.001) in 90 patients with chronic IHD Echocardiographic parameters (beyond LVEF) associated with ventricular arrhythmias in non-ischemic heart failure patients Imaging technique No. Cardiomyopathy Parameter Evidence Speckle tracking echocardiography 100 Sarcoidosis GLS GLS was independently associated with 1.4-fold increased risk of composite end point (including arrhythmias) 94 DCM GLS Mechanical dispersion Each 1% worsening in GLS was independently associated with ventricular arrhythmias, SCD and appropriate ICD therapy (HR 1.26, 95% CI 1.03 1.54;P = 0.02) Each 10 ms increment in mechanical dispersion was associated with a 1.20 increased risk for ventricular arrhythmias, SCD, and appropriate ICD therapy (95% CI 1.03 1.4; P = 0.02) 17
Mechanical dispersion Left panel shows synchronous contraction by longitudinal strain in a patient after myocardial infarction. Mid panel shows heterogeneous timing of contraction and pronounced mechanical dispersion in a patient after myocardial infarction with ventricular arrhythmias. Agenda Role of echo in arrhythmia management: Atrial Fibrillation: Evaluation of LA size Assessment of LV diastolic function Risk stratification (LAA thrombi detection) Role of intracardiac echo Ventricular arrhythmias and SCD: Ischemic Cardiomyopathy Non-ischemic cardiomyopathy Inheritable arrhythmogenic diseases: HCM, ARVD Role of echo in CRT optimization 18
HCM The diagnosis is based on the presence of abnormally increased LV wall thickness ( 15 mm) by any imaging modality not explained by loading conditions and in the absence of other diseases associated with LV hypertrophy HCM The most frequent genetic heart disease, usually caused by mutations of genes encoding sarcomeric proteins, transmitted with an autosomal dominant inheritance The annual incidence of SCD is 0.8%, with the highest prevalence among young patients 19
Estimation of SCD risk in HCM Risk stratification of patients with HCM using 2D speckle tracking echocardiography Speckle tracking echocardiographic LV strain analysis has demonstrated to correlate with the amount of replacement fibrosis in hypertrophic cardiomyopathy patients, and therefore it could be hypothesized that the assessment of LV strain may be also associated with increased risk of ventricular arrhythmias 20
Risk stratification of patients with HCM using 2D speckle tracking echocardiography On echocardiographic speckle tracking analysis, the magnitude of GLS is 13.8% (B). The study by Debonnaire et al showed that patients with a left ventricular GLS 14% had higher rates of appropriate ICD therapy compared with patients with more preserved GLS (< 14%) (C) ARVC Autosomal dominant inheritance disease with variable penetrance and phenotype expression characterized by replacement of right ventricular myocardium by fibrous and fatty tissue 21
1. Global or regional dysfunction and structural alterations Major 2D Echo Criteria Regional RV akinesia, dyskinesia, or aneurysm AND 1 of the following measured at end diastole: Minor - PLAX RVOT 32 mm (PLAX/BSA 19 mm/m 2 ), or - PSAX RVOT 36 mm (PSAX/BSA 21 mm/m 2 ), or - Fractional area change 33% CMR criteria Regional RV akinesia or dyskinesia or dyssynchronous RV contraction AND 1 of the following: - RV EDV/BSA 110 ml/m 2 (male) or 100 ml/m 2 (female) - RV ejection fraction 40% RV angiography criteria Regional RV akinesia, dyskinesia, or aneurysm 2D Echo Criteria Regional RV akinesia or dyskinesia or dyssynchronous RV contraction AND 1 of the following measured at end diastole: - PLAX RVOT 29 to <32 mm (PLAX/BSA 16 to <19 mm/m 2 ), or - PSAX RVOT 32 to <36 mm (PSAX/BSA 18 to <21 mm/m 2 ), or - Fractional area change > 33% 40% CMR criteria Regional RV akinesia or dyskinesia or dyssynchronous RV contraction AND 1 of the following: - RV EDV/BSA 100 to 110 ml/m 2 (male) or 90 to 100 ml/m 2 (female) - RV ejection fraction >40 to 45% Echo in ARVC 22
LV involvement in ARVC Clinical course of patients with ARVD/C with LV involvement versus isolated RV disease. Kaplan-Meier survival plots for LVEF(left) and LV involvement deformation imaging (right). Signs of LV involvement are associated with adverse outcome. Agenda Role of echo in arrhythmia management: Atrial Fibrillation: Evaluation of LA size Assessment of LV diastolic function Risk stratification (LAA thrombi detection) Role of intracardiac echo Ventricular arrhythmias and SCD: Ischemic Cardiomyopathy Non-ischemic cardiomyopathy Inheritable arrhythmogenic diseases: HCM, ARVD Role of echo in CRT optimization 23
CRT optimization CRT optimization Multiple methods, no gold standard for optimization The guidelines do not provide any specific recommendation 24
Methods Utilizing the MV inflow: The Ritter method The Iterative method Utilizing the LV outflow VTI The Ritter method The interval from the pacing spike to the end of the A wave on mitral inflow is measured at short and long AV delays. The difference in these time intervals is then subtracted from the long AV delay to calculate the optimal AV delay 25
The Iterative method 26
LVOT VTI method AV delay optimized to achieve the maximum stroke volume based on the aortic outflow tract VTI. In this case, the VTI increased from 16 to 23 cm with an increase in the AV delay from 80 to 150 ms. This can also be used in VV interval optimization Areas of uncertainty in AV optimization While the majority of the landmark trials of CRT incorporated some form of AV delay optimization at the time of implantation, definitive data supporting their superiority over an empiric, fixed AV delay are lacking Most available data involve hemodynamic studies demonstrating an acute improvement with optimization Most studies of routine optimization vs. fixed intervals have had mixed results 27
Take home messages Echocardiography can play a key role in risk stratification and management of patients with AF Transesophageal echocardiography provides accurate information about the presence of a thrombus in the atria and thromboembolic risk. The novel technique of intracardiac echocardiography has emerged as a popular and useful tool in the practice of interventional electrophysiology. Take home messages Left ventricular ejection fraction assessed with any imaging technique remains as an important criterion to identify the patients at risk of having ventricular arrhythmias or SCD Advanced echocardiographic imaging techniques evaluating the active deformation of the myocardium provided the incremental value for risk stratification in a variety of patients with cardiac disease. 28
Take home messages CRT optimization remains an important tool for non-responders Echocardiography based methods are available and diverse The choice of method used should be individualized as no clear data about the superior efficacy of any of the described methods exist to date Thank You 29