Noninvasive Cardiovascular Evaluation of the Competitive Athlete

1
Noninvasive Cardiovascular Evaluation of the
Competitive Athlete

• Gregory Piazza, M.D.
• Beth Israel Deaconess Medical Center
• March 19, 2008

2
Death on the Soccer Field

• Antonio Puerta, a midfielder for Sevilla FC,
  collapsed during a game on August 25, 2007.
• He regained consciousness and was walked to the
  locker room where he collapsed again.
• He was resuscitated and brought to the ICU of a
  nearby hospital.
• He suffered multiple prolonged cardiac arrests
  over the next several hours resulting in anoxic
  brain injury and multisystem organ failure.
• He died 3 days after his initial collapse at age
  22.
• Work-up revealed arrhythmogenic right ventricular
  cardiomyopathy (ARVC).

Antonio Puerta (November 26, 1984 August 28,
2007)
http//soccernet.espn.go.com/news/story?id457723
cc5901
3
Overview

• Although rare, sudden cardiac deaths (SCD) among
  young competitive athletes have substantial
  emotional and social impact upon the lay public
  and medical community.
• Because competitive athletes are often thought to
  exemplify health and invulnerability, their
  sudden deaths seem counterintuitive.

N Engl J Med 200334911
4
Overview

• Even with widespread availability of portable
  automated defibrillators at sporting events, the
  mortality for athletes after syncope or cardiac
  arrest remains high.
• An improved understanding of conditions that
  predispose to SCD among trained athletes has lead
  to a great interest in pre-participation
  screening.

N Engl J Med 200334911
5
Objectives

• Describe the physiological adaptations of the
  cardiovascular system to athletic training
• Highlight the epidemiology and causes of SCD in
  competitive athletes
• Discuss the role of noninvasive testing in the
  evaluation of competitive athletes
• Review the recommendations for pre-participation
  screening

6
The Physiological Adaptations in the Trained
Athlete

• Athletic training for competitive endurance
  (aerobic) or isometric (static or power) sports
  results in characteristic changes in cardiac
  structure and function.
• This physiological form of left ventricular (LV)
  hypertrophy is known as the athletes heart and
  must be distinguished from pathological
  conditions that may predispose to SCD.
• Depending on the nature of the exercise training
  benign increases in LV mass, wall thickness, and
  cavity size as well as left atrial volume may be
  observed in healthy athletes.

N Engl J Med 200334911
7
The Physiological Adaptations in the Trained
Athlete
Endurance Training
Isometric Training

• Increase in LV cavity size
• Minimal increase in LV wall thickness

• Increase in LV wall thickness out of proportion
  to increase in cavity size

Circulation 2000101336
8
The Athletes Heart
Gray area of overlap between the athletes
heart and cardiomyopathies.
N Engl J Med 200334911
9
The Athletes Heart

• The physiological changes of the athletes heart
  have been evaluated by cardiac MRI and 3-D echo.
• In a study of 30 patients, members of a mens
  professional rowing team were compared with
  sedentary untrained male subjects.
• Each patient underwent evaluation with 3-D echo
  and cardiac MRI.
• While 2-D echo significantly underestimated
  measurements, 3-D echo demonstrated good
  agreement with cardiac MRI.
• Compared with sedentary subjects, athletes had
  significantly increased LVEDV, LVESV, and LV
  mass.
• There were no differences in LVEF or the ratio of
  LV mass to LVEDV (LV remodeling index).

Heart 200692975
10
The Athletes Heart

• In another study, 23 male and 20 female endurance
  athletes were compared with age-matched controls
  using cardiac MRI.
• Male and female athletes demonstrated similar
  increases in LV and RV volumes and mass indices
  compared with controls.
• No gender-specific differences in the effect of
  training on LV and RV volumes, mass indices,
  ejection fractions, and LV to RV ratios of volume
  and mass indices were noted.

J Magn Reson Imaging 200624297
11
Competitive Sports
Classification of sports based on peak static and
dynamic components achieved during competition.
uptodateonline.com
12
Extrinsic Risk Factors for SCD

• The risk of SCD in competitive sports increases
  with burst exertion (rapid acceleration and
  deceleration common in basketball, tennis, and
  soccer).
• Extreme environmental conditions (temperature,
  humidity, and altitude) that affect blood volume
  and electrolyte balance also contribute to the
  risk.
• Progressive and systematic training to achieve
  higher levels of conditioning and performance may
  further increase the risk by resulting in a total
  cardiovascular demand that often exceeds that of
  competition.

Circulation 20041092807 J Am Coll Cardiol
2005451364
13
Other Extrinsic Risk Factors for SCD

• Cocaine abuse
• Amphetamine abuse
• Performance enhancing drugs (anabolic steroids)
• Dietary and nutritional supplements (including
  ephedra-containing products)

N Engl J Med 2001345351 J Am Coll Cardiol
2002391083
14
Epidemiology of Sudden Cardiac Death

• Although likely underestimated, the incidence of
  SCD among competitive athletes appears to be low,
  ranging from 1 per 50,000 to 1 per 300,000.
• In a study of Minnesota high school athletes, the
  incidence of SCD was 1 in 200,000.
• In a study of nearly 220,000 marathon runners,
  SCD occurred in 4 individuals.
• None had any prior cardiac symptoms
• 2 had competed in several previous marathons
• 3 had coronary disease on autopsy

JAMA 19962761999 J Am Coll Cardiol
1998321881 J Am Coll Cardiol 199628428
15
Causes of Sudden Cardiac Death

• Causes of SCD in athletes vary by age and
  geographic location.
• Among young competitive athletes (lt 35 years old)
  in the U.S., inherited or congenital heart
  conditions (such as hypertrophic cardiomyopathy)
  are the most common etiologies.
• Among masters athletes (gt 35 years old),
  coronary artery disease (CAD) appears to be the
  predominant cause of SCD.

J Am Coll Cardiol 200341974 Am J Cardiol
1980451292
16
Causes of Sudden Cardiac Death in Young Athletes

• In a U.S. registry of 236 young competitive
  athletes with SCD and structural heart disease on
  autopsy, the following conditions were reported
• Hypertrophic cardiomyopathy (HCM)(36)
• Anomalous coronary artery (13)
• Myocarditis (7)
• Ruptured aortic aneurysm (4)
• ARVC (4)
• Myocardial bridging (4)
• Aortic stenosis (3)
• CAD (3)
• Idiopathic dilated cardiomyopathy (3)
• Mitral valve prolapse (MVP)(3)

J Am Coll Cardiol 200341974
17
Causes of Sudden Cardiac Death in Young Athletes
Distribution of causes of SCD in 1435 young
competitive athletes. From the Minneapolis Heart
Institute Foundation Registry, 1980 to 2005.
Circulation 20071151643
18
Causes of Sudden Cardiac Death in Young Athletes

• In an analysis of data from over 6 million U.S.
  military recruits 35 years old, 64
  exercise-related deaths were due to an
  identifiable structural abnormality
• Anomalous coronary artery (33)
• Myocarditis (20)
• CAD (16)
• HCM (13)

Ann Intern Med 2004141829
19
Causes of Sudden Cardiac Death in Young Athletes

• In contrast, a series of 49 young athletes with
  SCD from Northern Italy demonstrated the
  following distribution
• ARVC (22)
• CAD (18)
• Anomalous coronary artery (12)
• MVP (10)
• Myocarditis (6)
• HCM (2)

N Engl J Med 1998339364
20
Hypertrophic Cardiomyopathy

• Incidence is approximately 1 in 500.
• It is a heterogeneous genetic disorder resulting
  in LV hypertrophy and fibrosis.
• Sudden death is most likely due to reentrant
  ventricular tachyarrhythmias.
• Most patients have an abnormal ECG.
• May be diagnosed by echo and cardiac MRI.

Marked septal hypertrophy with SAM
Late gadolinium enhancement consistent with
myocardial fibrosis
JAMA 20022871308
21
Anomalous Coronary Anatomy

• Incidence is likely underestimated.
• In SCD, most common anomaly is a left main
  coronary artery originating from the right sinus
  of Valsalva.
• May be suggested by chest pain or syncope with
  exercise but often SCD is the first symptom.
• Mechanism of ischemia is likely kinking or
  compression of the anomalous artery between the
  aorta and pulmonary trunk.
• ECG and echo are often normal.
• Best diagnosed by cardiac MRI, CT, or
  catheterization.

Two patients with left main coronary arteries
originating from right sinus of Valsalva
J Am Coll Cardiol 2000351493
22
Myocarditis

• May be preceded by a viral illness.
• Clinical findings may include chest pain and
  heart failure symptoms in an otherwise healthy
  young person.
• ECG often demonstrates diffuse repolarization
  changes.
• SCD is likely due to ventricular arrhythmias or
  atrioventricular conduction disease.
• May be suggested by LV systolic dysfunction (as
  detected by echo, cardiac MRI, or cath) in the
  absence of CAD.
• Cardiac MRI may demonstrate focally increased
  T2-signal consistent with myocardial inflammation
  and late gadolinium enhancement suggestive of
  fibrosis.

Inferolateral and lateral hypokinesis in a young
patient with myocarditis
Late gadolinium enhancement of the inferolateral
and lateral wall in the same patient
23
Aortic Aneurysm and Dissection

• In young athletes, aortic aneurysm and dissection
  is most often associated with aortopathy.
• Closely linked with inherited connective tissue
  disorders (Marfans syndrome).
• Marfans is inherited in an autosomal dominant
  fashion with an incidence of 1 in 10,000 to
  20,000.
• Characteristic morphological findings
  (arachnodactyly, hyperflexible joints) may be
  noted on examination.
• SCD occurs due to aortic aneurysm rupture or
  dissection.
• Diagnosed on basis of clinical criteria.
• Echo is recommended to evaluate for aortic
  disease (including AR).
• Cardiac MRI and CT also detect aortic pathology.

J Am Coll Cardiol 2005451340
24
Arrhythmogenic Right Ventricular Cardiomyopathy

• Characterized by fibrofatty infiltration of the
  RV free wall (may affect the LV).
• Symptoms include exercise induced palpitations,
  presyncope, or syncope.
• SCD is due to catecholamine-sensitive ventricular
  arrhythmias.
• ECG findings include increased QRS duration,
  epsilon waves in V1-2, and T wave inversions in
  the right precordium.
• Imaging may demonstrate RV dilatation and
  aneurysms.
• Echo and cardiac MRI are the most widely used
  noninvasive tests for ARVC.

Epsilon waves
Increased signal on T1-weighted imaging in the RV
free wall (left) and decreased signal on fat
suppressed imaging (right)
J Am Coll Cardiol 2001381773
25
Myocardial Bridging

• Myocardial bridging occurs when a portion of an
  epicardial coronary artery tunnels into the
  myocardium.
• Systolic vessel compression and delayed diastolic
  relaxation impair coronary blood flow in the
  intramyocardial segment.
• Although usually of little clinical consequence,
  myocardial bridging may infrequently result in
  exertional angina, infarction, and SCD.
• Myocardial bridging may be diagnosed on cardiac
  CT, MRI, or catheterization.

Contrast-enhanced EBCT image revealing an
intramyocardial segment of the LAD
N Engl J Med 20033491047
26
Aortic Stenosis

• Aortic stenosis (AS) in young athletes is most
  often due to congenital abnormalities of the
  aortic valve.
• Most common abnormality is a bicuspid aortic
  valve.
• More unusual etiologies include subvalvar and
  supravalvar aortic stenoses.
• Nearly all adult patients with SCD and congenital
  AS experience preceding symptoms.
• The majority of children may not have symptoms
  before SCD.
• Echo is the test of choice (although cardiac CT
  or MRI may be required to assess for concomitant
  aortic pathology).

Circulation 199387I16
27
Premature Coronary Artery Disease

• CAD in young patients is frequently asymptomatic.
• Therefore, its incidence is likely
  underestimated.
• In an autopsy study, advanced coronary stenoses
  were noted in 20 of men and 8 of women aged
  30-34 years.
• 19 and 8 of men and women aged 30-34 years,
  respectively, had 40 stenosis of the LAD.
• Coronary artery disease is the most common cause
  of SCD among masters athletes (gt 35 years old).

Circulation 2000102374
28
Idiopathic Dilated Cardiomyopathy

• Idiopathic cardiomyopathy is a relatively
  uncommon cause of SCD in young competitive
  athletes (3).
• The mechanism of SCD is most often reentrant
  ventricular tachyarrhythmia originating from
  areas of abnormal myocardium.
• Bradyarrhythmia or asystole may lead to SCD if
  cardiomyopathic process involves the conduction
  system.

Late gadolinium enhancement in a patient with
cardiomyopathy and normal coronary arteries
29
Mitral Valve Prolapse

• Although its relationship to tachyarrhythmia has
  been controversial, MVP is associated with an
  increased risk of SCD.
• However, the increased risk of SCD seems to
  correlate with the degree of mitral valve
  pathology and MR.
• In one study, the annual SCD mortality was
  significantly increased (from 0.9 to 1.9) in
  patients with advanced mitral valve pathology
  compared with patients with isolated MVP (no MR)
  or the general population.
• Late gadolinium enhancement of the papillary
  muscles may be noted in some patients with MVP
  suggesting the presence of scarring or fibrosis.

Late gadolinium enhancement of the anterolateral
papillary muscle in a patient with MVP
Am Heart J 19871131298
30
Other Congenital Heart Disease

• In addition to arrhythmic causes, cyanosis during
  exercise in the setting of adult congenital heart
  disease with right-to-left shunt may lead to
  syncope and SCD.
• Cardiac arrest is an unusual first presentation
  of adult congenital heart disease as most are
  symptomatic and therefore diagnosed before SCD.
• Adult congenital heart disease may be diagnosed
  by echo, cardiac CT, or MRI.
• Cardiac MRI currently offers the best definition
  of the complex anatomy of repaired and unrepaired
  congenital heart disease.

31
Sudden Cardiac Death in the Absence of Structural
Heart Disease

• SCD in competitive athletes may also occur in the
  absence of structural heart disease.
• Causes of SCD in structurally normal hearts
  include inherited arrhythmia syndromes such as
• Long QT syndrome
• Brugada syndrome
• Catecholaminergic polymorphic VT
• Wolf-Parkinson-White syndrome
• Congenital short QT syndrome
• In addition, idiopathic VF and commotio cordis
  may result in SCD among competitive athletes.

32
Long QT Syndromes

• Often acquired, long QT syndrome can be
  inherited.
• Long QT syndromes may result in polymorphic VT
  (torsade de pointes) and SCD.
• Among inherited long QT syndromes, precipitants
  and prognosis vary.

Examples of long QT syndromes
N Engl J Med 20081131298
33
Brugada Syndrome

• Autosomal dominant disorder resulting in
  increased risk of SCD.
• Multiple mutations in the cardiac sodium channel
  SCN5A have been described.
• Characterized by RBBB and ST segment elevations
  in V1-V3 on ECG.

Typical ECG pattern for Brugada Syndrome
uptodateonline.com
34
Catecholaminergic Polymorphic VT

• Also known as familial polymorphic VT,
  catecholaminergic polymorphic VT typically
  manifests itself in childhood or adolescence.
• SCD may occur in the setting of emotional or
  physical stress.
• Like LQT1, SCD while swimming has been described.
• Several mutations have been described including
  in the cardiac ryanodine receptor and
  calsequestrin 2 genes.

Circulation 200210669
35
Wolf-Parkinson-White

• WPW syndrome has been associated with an
  increased risk of SCD.
• The mechanism of SCD is most often atrial
  fibrillation or AVNRT that degenerates to VF.
• In up to 25 of patients with SCD due to WPW,
  pre-excitation and arrhythmias have been
  previously undiagnosed.

Typical pre-excitation pattern for WPW
J Am Coll Cardiol 1991181711 uptodateonline.com
36
Congenital Short QT Syndrome

• Congenital short QT syndrome is a rare autosomal
  dominant disorder associated with SCD due to VF.
• Multiple genetic abnormalities have been
  described including gain-of-function mutations in
  potassium channel genes.
• Short QT is defined as a corrected QT interval
  (QTc) 340 msec.
• Patients often develop atrial fibrillation at a
  young age .
• Not all patients with short QTc carry an
  increased risk of SCD.

Circulation 2003108965
37
Idiopathic VF

• Also called primary electrical disease,
  idiopathic VF is diagnosed when SCD occurs in a
  structurally normal heart and other arrhythmic
  disorders are excluded.
• May account for up to 5 of SCD cases.
• Idiopathic VF is more common in men and has a
  mean onset of 36 years.
• A history of syncope precedes SCD in up to 25 of
  patients.

Am Heart J 1990120661
38
Commotio Cordis

• Commotio cordis describes SCD that occurs
  following precordial trauma.
• A registry analysis revealed that 62 of cases
  occurred during organized or recreational
  sporting activities (baseball, hockey).
• In an animal model, low-energy impact to the
  chest wall just before the peak of the T wave
  produced VF, while impact during the QRS complex
  produced complete heart block.
• Frequency of VF was related to the hardness of
  the projectile and velocity of impact.
• In one series, only 16 of individuals survived
  an arrhythmic event in the setting of commotio
  cordis.

JAMA 20022871142 N Engl J Med 1998 3381805
39
Commotio Cordis
Fatal commotio cordis in a 14-year-old boy during
a karate match.
N Engl J Med 200334911
40
Syncope in Competitive Athletes

• Syncope in competitive athletes without known
  structural heart disease is most often due to
  neurocardiogenic, or vasovagal, mechanisms.
• However, the diagnosis of neurocardiogenic
  syncope in this patient population is a diagnosis
  of exclusion.
• Careful evaluation warrants a detailed history,
  physical examination, and ECG.
• Echocardiography, exercise treadmill testing,
  cardiac MRI, and electrophysiological testing may
  be required to exclude structural and
  dysrhythmia-related causes of syncope.

41
Cardiovascular Events in Spectators

• The emotional stress of watching competitive
  sports may increase the risk of cardiovascular
  events.
• A recent study demonstrated an increased
  incidence of cardiac emergencies among German men
  and women on days that the German team was
  playing a 2006 World Cup match compared to
  non-match days (incidence ratio 2.66, 95 CI
  2.33-3.04 plt0.001.
• The incidence of STEMI, NSTEMI, and arrhythmia
  increased by a factor of 2.5, 2.6, and 3.1,
  respectively, during match days.

Daily cardiovascular events from May 1 to July 31
in 2003, 2005, and 2006. Numbers 1-7 correspond
to German soccer matches during the 2006 World
Cup (8 Final, Italy v. France).
N Engl J Med 2008358475
42
Screening

• Due to the devastating nature of SCD and the
  potential to prevent such deaths by diagnosing
  associated disorders noninvasively, clinicians
  have a strong incentive to screen athletes.
• However, the following obstacles prevent
  widespread screening with noninvasive testing
• Large number of competitive athletes (8 million
  in the U.S., including high school, collegiate,
  professional)
• Low prevalence of underlying congenital heart
  disease
• Number of disorders to consider, each with
  different optimal testing modalities
• Impact of false-positive studies (substantial
  when screening for rare diseases possible
  medicolegal implications)
• No randomized trials evaluating the impact of
  pre-participation screening on the incidence of
  SCD

N Engl J Med 200334911
43
Screening

• In an observational series from Italy, a
  mandatory screening program including ECG was
  associated with a decrease in the annual
  incidence of SCD in athletes from 3.6 to 0.4 per
  100,000 person-years from 1980 to 2004.
• AHA guidelines differ from those of the European
  Society of Cardiology (ESC) and the International
  Olympic Committee (IOC) such that routine
  noninvasive testing (including ECG) is not
  recommended.

JAMA 20062961593 Circulation 20071151643
44
AHA Screening Recommendations

• Younger competitive athletes (lt35)
• Complete personal/family history and physical
  exam
• Performed by physicians or certified
  non-physicians
• q2 years for high school and yearly for
  college/pro
• Masters athletes (gt35)
• Complete personal/family history and physical
  exam
• Exercise testing for moderate-to-high risk
  patients (men gt40, women gt50 with one or more CAD
  risk factors symptoms suggestive of CAD 65
  regardless of risk factors/symptoms)
• Recreational athletes
• No explicit AHA guidelines exercise testing
  recommended in patients at high risk for CAD

Circulation 20071151643
45
12-Element AHA Pre-Participation Screening
Recommendations

• Personal history (confirmed by parent if minor)
• Exertional chest discomfort
• Unexplained syncope/presyncope
• Excessive exertional fatigue/dyspnea
• Prior heart murmur
• Elevated blood pressure
• Family history (confirmed by parent if minor)
• Premature death due to heart disease before age
  50
• Disability due to heart disease in relative lt50
• Specific knowledge of certain cardiac conditions
  (HCM, other CM, ion channelopathy, Marfans,
  arrhythmias)
• Physical examination
• Cardiac exam (supine and standing)
• Femoral pulses
• Physical stigmata of Marfans
• Bilateral blood pressure readings
• Positive finding of any 1 element warrants
  referral to cardiovascular specialist /- further
  testing

Circulation 20071151643
46
Activity Restriction Recommendations

• The 26th Bethesda Conference guidelines have
  established clear recommendations for the
  athletic eligibility and restriction of athletes
  with conditions associated with SCD.
• The decision to remove athletes from eligibility
  may be associated with complex social and
  medicolegal ramifications.
• A U.S. appellate court has ruled that the
  Bethesda Conference report can be used by
  clinicians to determine an athletes eligibility.
• Guidelines such as the Bethesda Conference report
  have been endorsed as a means for resolving
  medicolegal disputes involving the eligibility of
  young athletes.

N Engl J Med 200334911
47
Conclusions

• SCD in competitive athletes may result from a
  variety of disorders that may be detected by
  noninvasive testing.
• Noninvasive testing must be interpreted carefully
  in order to distinguish the physiological effects
  of exercise training from pathology.
• AHA guidelines do not endorse routine
  pre-participation screening with noninvasive
  testing.
• However, noninvasive testing plays a critical
  role in the evaluation of competitive athletes
  with positive findings on screening history and
  physical examination.