1. Dr V S R BhupalATHLETES HEART-A SHORT REVIEW

2. In highly conditioned athletes, a bigheart-the literal, not themetaphorical kind- is a sign ofhealth and power. But in somecases, it can be a deadly burden. ATHLETES HEART-A SHORT REVIEW 3. OVERVIEW DEFINITION HISTORY PHYSIOLOGY CHAMBER MORPHOLOGY 12 LEAD ECGS ARRHYTHMIAS ATHLETES HEART AND CARDIOVASCULARDISEASE LONG TERM CONSEQUENCESATHLETES HEART-A SHORT REVIEW 4. DefinitionAthletes heart means characteristic enlargement/hypertrophy/ of the myocardium in response to repeatedexercise stimuliPrincipal features of athletes heart Cardiac enlargement to allow for increased maximal strokevolume (SV) and cardiac output (Q) adaptations that drive the increase inoxygen delivery in the trained state since no training effect isevident in maximal heart rate (HR max)ATHLETES HEART-A SHORT REVIEW 5. HISTORY The concept that the cardiovascular system of trainedathletes differs structurally and functionally from others inthe normal general population remarkably extends over acentury. Henschen is credited with the first description in 1899,using only a basic physical examination with carefulpercussion to recognize enlargement of the heart caused byathletic activity in cross-country skiers. Henschen concluded that both dilatation andhypertrophy were present, involving both the left and rightsides of the heart, and that these changes were normal andfavorable: Skiing causes an enlargement of the heart whichcan perform more work than a normal heart.ATHLETES HEART-A SHORT REVIEW 6. Similar observations were made during the same year byEugene Darling of Harvard University in universityrowers. In the early 1900s, Paul Dudley White studied radialpulse rate and pattern among Boston Marathoncompetitors, and was the first to report marked restingsinus bradycardia in long distance runners. Early chest radiography work confirmed the physicalexamination findings of Darling and Henschen by showingglobal cardiac enlargement in trained athletes.ATHLETES HEART-A SHORT REVIEW 7. The subsequent development of ECG enabledwidespread study of electric activity in the heart of thetrained athlete. Advanced echocardiographic techniques and magneticresonance imaging have begun to clarify importantfunctional adaptations that of athletes heart.ATHLETES HEART-A SHORT REVIEW 8. PHYSIOLOGY Cardiovascular adaptations differ with respect to thetype of conditioning:endurance training(dynamic,isotonic, or aerobic) such as long-distancerunning and swimming; and strengthtraining(static,isometric, power, or anaerobic) such aswrestling, weightlifting,or throwing heavy objects. Sports such as cycling and rowing are examples ofcombined endurance and strength exercise.ATHLETES HEART-A SHORT REVIEW 9. Acute response to enduranceexerciseIncrease in maximum oxygen consumption cardiac output stroke volume systolic blood pressureDecrease in Peripheral vascular resistance.ATHLETES HEART-A SHORT REVIEW 10. Acute response to strengthconditioningMild increase in oxygen consumption cardiac outputSubstantial increase in Blood pressure peripheral vascular resistance heart rate.ATHLETES HEART-A SHORT REVIEW 11. Long-term cardiovascular adaptation to dynamictraining produces increased maximal oxygen uptakedue to increased cardiac output and arteriovenousoxygen difference. Strength exercise results in little or no increase inoxygen uptake. Endurance exercise predominantly produces volumeload on the left ventricle (LV), and strength exercisecauses largely a pressure load.ATHLETES HEART-A SHORT REVIEW 12. The maximum oxygen consumption represents thelargest amount of oxygen a person can use whileperforming dynamic exercise involving a large part oftotal muscle mass. It is determined by the equationATHLETES HEART-A SHORT REVIEW 13. Morganroth hypothesis, 1977M-mode echocardiography-two differentmorphological forms of athletes heart:eccentric LV hypertrophy - increase in LV cavitydimensions,proportional increase in left ventriclewall thickeness /LVWT/ to normalise myocardialstrain, typically in pure aerobic,endurance sportsconcentric LV hypertrophy - increase in LVWTto normalise increased wall tension with rise inpressure, typically in resistance or strength trainingathletesATHLETES HEART-A SHORT REVIEW 14. ATHLETES HEART-A SHORT REVIEW 15. CHAMBER MORPHOLOGYATHLETES HEART-A SHORT REVIEW 16. Training induces cardiac remodeling in 50% of trainedathletes. IncreasedLV,RV and LA size and volume . NormalSystolic and diastolic functionATHLETES HEART-A SHORT REVIEW 17. Marked enlargement of the LV chamber (60 mm)occurs in 15% of highly trained athletes. This chamber enlargement may occasionally beaccompanied by a relatively mild increase in absoluteLV wall thickness that exceeds upper normal limits(range 13 to 15 mm).ATHLETES HEART-A SHORT REVIEW 18. LV remodeling may develop rapidly, or moregradually, after the initiation of vigorous conditioning. Changes are reversible with cessation of training -most impressive in endurance athletes. Athletes show relatively small increase 10% to 20% inwall thickness or cavity size,and these values remainwithin accepted normal limits.ATHLETES HEART-A SHORT REVIEW 19. ATHLETES HEART-A SHORT REVIEW 20. ATHLETES HEART-A SHORT REVIEW 21. Longitudinal studies of exercise training andcardiac morphology in athletes LVIDd can be further augmented with training mainly withendurance training in elite athletes despite preexistingincrease in cardiac internal dimensionsATHLETES HEART-A SHORT REVIEW 22. Longitudinal studies in sedentary individuals Exercise programs in sedentary or untrained individualsresult in significant enlargement of LV cavity, increases inLVWTATHLETES HEART-A SHORT REVIEW 23. Conclusions1. Athletes exhibit significant cardiac adaptationswith absolute LVM increase in both enduranceand strength trained athletes compared withcontrols2. LVM and LVMi are larger in endurance-trainedathletes compared with strengths-trainedathletes3. Volume of training influences the degree of increasein LVM in endurance athletesATHLETES HEART-A SHORT REVIEW 24. IMPACT OF VARIOUS VARIABLESON LV DIMENSIONSATHLETES HEART-A SHORT REVIEW 25. Left atrial remodeling is present in highly trainedathletes, most commonly those in combined static anddynamic sports (cycling and rowing), and is associatedwith LV cavity enlargement and volume overload. Increased transverse left atrial dimensions (40 mm)are present in 20% of athletes and more substantiallyenlarged dimensions (45 mm) are evident in 2%.ATHLETES HEART-A SHORT REVIEW 26. Left atrial enlargement is benign and largely confinedto training in endurance sports, is rarely associatedwith atrial fibrillation(1% of cases).ATHLETES HEART-A SHORT REVIEW 27. 12 LEAD ECGS A spectrum of abnormal ECG patterns is present in40% of trained athletes, occurring 2-fold morecommonly in men than women, and particularly inthose participating in endurance sports.ATHLETES HEART-A SHORT REVIEW 28. The Athletes Heart & ECGCommon abnormalities seen in an athlete Sinus bradycardia (up to 91%) may be less than 50 beats / minute reflects predominance of vagal tone may exhibit junctional escape rhythm Sinus arrhythmia 1st and 2nd (type I) degree AV block (10% - 33%) Left ventricular hypertrophy (up to 76%) Incomplete RBBB (up to 51%) QRS width between .10 and .12 seconds Early repolarization mild J-point and ST segment elevation differential diagnosis Brugada Syndrome elevated J-point swoops into a negative T-wave Premature atrial & ventricular contractionsATHLETES HEART-A SHORT REVIEW 29. ATHLETES HEART-A SHORT REVIEW 30. The Athletes Heart & ECG38 year old male distance runner with sinus bradycardia (42 bpm) with periodsof junctional rhythm (red arrows)ATHLETES HEART-A SHORT REVIEW 31. The Athletes Heart & ECG41 year old male distance runner with J-point and ST-segment elevation (arrows)depicting early repolarizationATHLETES HEART-A SHORT REVIEW 32. The Athletes Heart & ECGLVH in an athletePatholigical LVHNote strain pattern in lateral precordial leadsATHLETES HEART-A SHORT REVIEW 33. The Athletes Heart & ECGEarly repolarization pattern ofBrugada Syndrome (elevated ST-segmentgoes into a negative T-wavein V1 and V2)Early repolarization pattern ofan athlete (note voltage criteriafor LVH is borderline)Brugada Syndrome predisposes oneto Ventricular Tachycardia /Ventricular FibrillatioAnTH.LETES HEART-A SHORT REVIEW 34. The Athletes Heart & ECGCauses of Sudden Death in athletes Long QT syndrome QT interval longer than .44 seconds Predisposition to Torsades de Pointes, a type of V-tach Hank Gathers died in 1990 while playing basketball (went off meds) Hypertrophic Cardiomyopathy of the Left Ventricle Symptoms: chest pain, dyspnea, syncope Predisposition to V-Tach Arrhythmogenic Cardiomyopathy of the Right Ventricle Familial condition where RV myocardium is replace by fibro-fatty tissue Predisposition to V-tach Congenital Coronary Artery Anomalies Pete Maravich had no left coronary artery died of MI at 40 years of ageATHLETES HEART-A SHORT REVIEW 35. ATHLETES HEART-A SHORT REVIEW 36. Distinctly abnormal and bizarre ECGs, intuitivelysuggestive of cardiac disease, are encountered in animportant minority of elite athletes (15%). Majority of such ECGs represent extrememanifestations of physiological athletes heart.ATHLETES HEART-A SHORT REVIEW 37. ATHLETES HEART-A SHORT REVIEW 38. ARRHYTHMIASATHLETES HEART-A SHORT REVIEW 39. Ambulatory (Holter) ECG monitoring in trainedathletes documented substantial ectopy with frequentpremature beats and complex ventriculartachyarrhythmias (including couplets and bursts ofnonsustained ventricular tachycardia) in manyindividuals. These findings suggest that a variety of arrhythmiasare part of the athletes heart spectrum .ATHLETES HEART-A SHORT REVIEW 40. Such rhythm disturbances have not been associatedwith adverse clinical events and are usually abolishedor substantially reduced after relatively brief periods ofdeconditioning . Even in athletes with heart disease, resolution ofventricular tachyarrhythmias with deconditioning iscommon and may represent a potential mechanism bywhich sudden death risk is reduced by withdrawal ofthese individuals from training and competitionATHLETES HEART-A SHORT REVIEW 41. ATHLETES HEART-A SHORT REVIEW 42. A few observational studies have reported mild-tomoderate post race elevations in biochemical cardiac-specificmarkers (plasma cardiac troponin T and I)suggestive of transient myocardial injury in someparticipants after prolonged and strenuous enduranceathletic events, such as triathlons and marathons. At present, there is no evidence that these subclinicalfindings are associated with permanent clinicalconsequences. Some studies have also identified transient and reversiblesystolic and diastolic dysfunction after extreme athleticevents.ATHLETES HEART-A SHORT REVIEW 43. ATHLETES HEART-A SHORT REVIEW 44. ATHLETES HEART-A SHORT REVIEW 45. Athletes Heart and CardiovascularDisease Distinguishing physiologically based athletes heartfrom a variety of structural heart diseases is importantbecause- This may represent the basis for disqualification fromcompetitive sports to reduce the risk of sudden death. High risk athletes may become candidates for animplantable defibrillator and prophylactic preventionof sudden death.ATHLETES HEART-A SHORT REVIEW 46. 2% of elite adult male athletes have been reported toshow modestly increased LV wall thickness of 13 to 15mm, which defines a gray zone of overlap betweenthe extreme expressions of athletes heart and a mildHCM Phenotype. This ambiguity can be resolved by the application of anumber of noninvasive parameters, such as -1)reduced cardiac mass with short deconditioningperiods (best assessed with serial magnetic resonanceimaging)2)absolute LV diastolic dimension 55 mmATHLETES HEART-A SHORT REVIEW 47. HCM diagnosis would be favored by--Abnormal Doppler-derived LV diastolic filling orrelaxation indices-By the existence of a family member with HCM.ATHLETES HEART-A SHORT REVIEW 48. ATHLETES HEART-A SHORT REVIEW 49. ATHLETES HEART-A SHORT REVIEW 50. Magnetic resonance imaging has value in resolving theHCM-versusathletes heart differential diagnosis inselected athletes by virtue of its superiority overechocardiography in identifying segmental LVhypertrophy in the antero lateral free wall or apex.ATHLETES HEART-A SHORT REVIEW 51. Critical evaluation of cardiacmorphology measurementEchocardiographic imaging Large methodological error range in measuring LVID, LVWTMagnetic resonance imaging (MRI) Highly accurate and reproducible technique for determiningLVM and cardiac dimensions Drawback- expensive,limited availibilityMRI x Echocardiography (DeCastro, 2006) 18 male, elite-level rowers,12 untrained sedentary subjects Echocardiography underestimation LVIDd and LVM relativeto MRIATHLETES HEART-A SHORT REVIEW 52. ATHLETES HEART-A SHORT REVIEW 53. Rapid commercial laboratory testing is now availablefor both HCM and cardiac ion channel mutations withthe potential for achieving a DNA-based diagnosis. If a proband is positive for one of the known disease-causingmutant genes in the panel, the result isdefinitive.ATHLETES HEART-A SHORT REVIEW 54. Marked LV cavity enlargement in an athlete, even inthe absence of cardiac symptoms, may intuitively raisethe differential diagnosis between physiologicalhypertrophy and pathological cardiomyopathies,particularly when ejection fraction is judged to be atthe lower range of normal or mildly depressed. This difficult clinical situation can often be resolvedby surveillance with serial testing of ejection fractionat rest and with exercise, after disqualification fromsports.ATHLETES HEART-A SHORT REVIEW 55. Complex and frequent ventricular tachyarrhythmiasevident on ambulatory Holter ECG in trained athleteswithout cardiovascular abnormalities can raise thepossibility of disease states such as myocarditis, forwhich a high index of clinical suspicion is required. Periods of forced deconditioning may not be useful inresolving such differential diagnoses, becausedetraining is associated with reduction of ventriculartachyarrhythmias in athletes both without and withunderlying pathological substrates.ATHLETES HEART-A SHORT REVIEW 56. Long-Term Consequences ofAthletes Heart Extreme LV remodeling evident in some highly trainedathletes has intuitively raised a concern of whethersuch exercise-related morphological adaptations arealways innocent. 15% of highly trained athletes show striking LV cavityenlargement, with end-diastolic dimensions 60 mm,similar in magnitude to that evident in pathologicalforms of dilated cardiomyopathy.ATHLETES HEART-A SHORT REVIEW 57. One longitudinal echocardiographic study reportedincomplete reversal of extreme LV cavity dilatation . With deconditioning substantial chamberenlargement persisted in 20% of retired anddeconditioned former elite athletes after 5 years.ATHLETES HEART-A SHORT REVIEW 58. There is no evidence at present showing that athletesheart remodeling leads to long-term diseaseprogression,cardiovascular disability, or suddencardiac death. The possibility that persistence of extreme remodelingafter prolonged and intensive conditioning willultimately convey deleterious cardiovascularconsequences to some athletes is perhaps unlikely butat this time cannot be excluded with certainty.ATHLETES HEART-A SHORT REVIEW 59. THANK YOUATHLETES HEART-A SHORT REVIEW