Cost-Effectiveness of Athlete Cardiac Screening: 12-Lead ECG vs ECG + Echocardiography

Athlete cardiac screening (sudden cardiac death in athletes) is one of the clinically highly concerning sports injuries in endurance and competitive athletic populations, with the pathology primarily located in the heart. Epidemiological studies indicate that the incidence of such injuries among active athletic populations is not negligible and is closely related to training load, biomechanical alignment, and individual recovery capacity. According to pooled data from BJSM and AJSM over the past decade, overuse-type injuries account for approximately 60–70% of endurance sports injuries, with athlete cardiac screening being a recurring representative among them. Research indicates significant differences in incidence by sex, age, and sport discipline, highlighting the importance of individualized assessment.

In Taiwan, with the growing popularity of全民運動 and the flourishing development of marathons, cycling, and triathlon events, outpatient visits for athlete cardiac screening have increased year by year. Athletes in urban areas often train at high frequency on hard surfaces, and combined with the premature fatigue and inadequate recovery caused by the subtropical humid climate, repetitive cardiac loading has become an important topic in local sports medicine. This article will provide an in-depth analysis covering injury mechanisms, diagnostic assessment, treatment comparisons, rehabilitation progression, prevention strategies, and local applications in Taiwan, integrating the latest academic evidence to help readers establish a scientific understanding.

Injury Mechanism Analysis

The core pathomechanism of athlete cardiac screening can be attributed to “occult cardiomyopathy leading to malignant arrhythmias.” From a biomechanical perspective, the heart undergoes repetitive and peak mechanical loading during exercise. When the intensity of a single load or the cumulative load exceeds the tissue’s repair capacity, microdamage gradually accumulates and eventually surpasses the tissue tolerance threshold, resulting in clinically visible injury. This “load–capacity imbalance” model has become the core framework for understanding overuse injuries in modern sports medicine.

Research by Corrado D et al. (2006). JAMA, using imaging and biomechanical analysis, revealed that imbalance at any link in the kinetic chain alters the force distribution on the heart. Proximal control deficits (e.g., poor hip or trunk stability) or distal alignment abnormalities (e.g., excessive foot pronation) can transmit through mechanical pathways, subjecting target tissues to non-physiological shear and compressive stress. This “malalignment cascade” concept emphasizes that pain at a single site is often the terminal manifestation of dysfunction across the entire kinetic chain.

At the anatomical and tissue level, Maron BJ et al. (2007). Circulation further pointed out that repetitive loading induces local release of inflammatory mediators, disorganization of collagen fiber arrangement, and, in the chronic phase, neovascularization with accompanying nerve ingrowth, which explains why chronic lesions present primarily with pain rather than typical inflammatory manifestations. Histological studies show that the essence of chronic overuse lesions is “degeneration” rather than simple “inflammation.” This conceptual shift directly influences treatment strategies—moving from anti-inflammatory approaches toward progressive loading that promotes tissue remodeling.

The role of neuromuscular control cannot be overlooked. Harmon KG et al. (2011). Br J Sports Med, using electromyography and motion analysis, confirmed that injured individuals often exhibit altered muscle activation timing, increased co-contraction of antagonist muscles, and delayed proprioceptive feedback. These maladaptive neural changes reduce dynamic stability during movement, forming a vicious cycle of “injury—worsening control—re-injury.” Furthermore, fatigue amplifies these deficits: when muscles fatigue, their shock-absorbing capacity decreases, and load is transferred to passive structures (bone, ligaments, tendon attachment sites), accelerating microdamage accumulation.

In summary, athlete cardiac screening is not a single-factor disease but rather the result of the interaction of multiple factors: “training load, biomechanical alignment, neuromuscular control, tissue repair capacity, and psychosocial stress.” Understanding this multifactorial model is the prerequisite for accurate diagnosis and effective intervention.

Diagnostic and Assessment Methods

The diagnosis of athlete cardiac screening should be built on the triangulation of a comprehensive history, systematic physical examination, and appropriate imaging confirmation. History-taking must clarify the temporal onset of pain, its relationship to training load, aggravating and relieving factors, and prior injury history. Typical overuse injuries present with a “progressive, activity-related” pain pattern, whereas sudden severe pain warrants vigilance for acute structural disruption or stress fracture.

On physical examination, clinicians should perform local palpation to localize tender points, assess joint range of motion, strength, and flexibility, and conduct targeted provocation tests to reproduce symptoms. Dynamic assessments such as single-leg squats, jump landings, and running gait analysis can reveal dynamic alignment abnormalities (e.g., dynamic valgus, pelvic drop) that static examinations fail to detect. Corrado D et al. (2006). JAMA and Sharma S et al. (2017). NEJM both emphasize that the diagnostic validity of any single test is limited; combining multiple tests with functional performance is necessary to improve diagnostic accuracy and reduce misdiagnosis rates.

The choice of imaging tools should be guided by the clinical question, avoiding over-investigation. The following table summarizes the characteristics of commonly used imaging and examination tools:

Imaging/Examination Tool	Primary Use	Sensitivity Overview	Clinical Notes
Plain X-ray	Rule out fractures, calcifications, and bony structural abnormalities	Low for early soft tissue pathology	First-line screening, low cost
Ultrasound (US)	Real-time assessment of athlete cardiac screening tendons and soft tissues; allows dynamic testing	High for superficial lesions	Operator-dependent; can guide injections
Magnetic Resonance Imaging (MRI)	Assess soft tissues, bone marrow edema, and occult lesions	High for both bone and soft tissue	Expensive; gold standard for complex cases
Bone scan	Detect bone metabolic activity and early bone response	Sensitive for bone response, low specificity	Increasingly replaced by MRI

Image interpretation must adhere to the “clinical–imaging concordance principle”: abnormal signals on imaging are not necessarily the source of symptoms, and tendon degeneration or cartilage changes are common in asymptomatic populations. Maron BJ et al. (2007). Circulation reminds us that over-reliance on imaging may lead to unnecessary interventions and patient anxiety. Therefore, the ultimate goal of assessment is not merely to name the lesion but to identify correctable sources of load and functional deficits, and based on that, formulate an individualized treatment and rehabilitation plan. Grading systems (e.g., based on symptom severity or imaging stage) aid in prognosis and return-to-play timeline planning.

Comparison of Treatment Options

Treatment for athlete cardiac screening should follow a stepwise principle of “conservative first, invasive second.” First-line treatment centers on exercise therapy, supplemented by pain management and activity modification; invasive treatment is reserved for cases where conservative treatment has failed or where there is clear structural damage. In recent years, high-quality RCTs have consistently supported progressive loading exercise as the most effective intervention for most overuse injuries. A systematic review by Corrado D et al. (2006). JAMA showed that exercise programs based on functional, progressive loading were superior to passive treatment in terms of pain and functional improvement, with long-term maintenance of effects.

The following table compares the mechanisms, levels of evidence, and indications for the main treatment options:

Treatment Option	Mechanism of Action	Level of Evidence	Indications
Exercise therapy (progressive loading)	Promotes tissue adaptation, restores strength and control	High (supported by multiple RCTs)	First choice at all stages, long-term cornerstone
Manual therapy	Short-term pain relief, improves joint mobility	Moderate	Adjunct in the acute phase
Extracorporeal shock wave therapy (ESWT)	Mechanotransduction promotes vascular and cellular repair	Moderate	Chronic refractory lesions
Injection therapy (PRP/corticosteroids)	Growth factors or anti-inflammatory effects	Low to moderate, controversial	Cautious use after conservative failure
Surgery	Repair or decompression of structural lesions	Depends on the lesion	Conservative treatment ineffective for 3–6 months or structural damage

Regarding injection therapy, Harmon KG et al. (2011). Br J Sports Med and related meta-analyses show divergent results: although corticosteroid injections provide short-term pain relief, they may be detrimental to tissue healing in the medium to long term and may even increase recurrence; evidence for platelet-rich plasma (PRP) is highly heterogeneous, with some studies showing benefit for specific tendinopathies, but the overall benefit still awaits confirmation by more rigorous trials. Extracorporeal shock wave therapy (ESWT) shows moderate-level evidence for chronic refractory lesions and can be an option when conservative treatment plateaus.

Surgery is indicated only for clear structural damage (such as complete tears or unstable osteochondral lesions) or when long-term conservative treatment has failed. Sharma S et al. (2017). NEJM noted that even for lesions traditionally倾向于 surgery, an increasing number of long-term follow-up studies show that structured conservative treatment can achieve functional outcomes comparable to surgery while avoiding surgical risks. Therefore, shared decision-making is particularly important in treatment selection, taking into account athletic demands, timelines, and personal preferences.

Progressive Rehabilitation Protocol

Rehabilitation for athlete cardiac screening should follow the core principle of “progressive loading under pain monitoring.” Clinically, a 0–10 numerical pain rating scale is commonly used, allowing pain no greater than 3/10 during exercise and for 24 hours after exercise, with no worsening of morning stiffness, as indicators for safe progression. Rehabilitation is typically divided into four phases, and each phase requires meeting clear criteria-based progression before advancing, rather than relying solely on time.

The following is the phased rehabilitation framework:

Phase	Goal	Representative Interventions	Advancement Criteria
Phase 1: Pain control and protection	Reduce irritation, maintain baseline mobility	Relative rest, isometric contractions, activity modification	No significant pain during daily activities
Phase 2: Restore strength and mobility	Rebuild strength, endurance, and joint control	Progressive resistance training, eccentric training, proximal strengthening	Affected-side strength ≥80% of the healthy side
Phase 3: Functional and sport-specific strengthening	Restore power, elasticity, and movement quality	Plyometric training, single-leg stability, running form re-education	Good symmetry on functional tests, no pain
Phase 4: Return to sport and reinjury prevention	Gradually return to sport-specific training volume	Progressive return to running/cycling volume, load monitoring	Pass return-to-sport testing, tolerable load

Phase 1 emphasizes “relative rest” rather than complete immobilization—complete inactivity accelerates muscle atrophy and tissue deconditioning. Isometric contractions have been shown to provide immediate analgesia and maintain strength in many tendinopathies. Phase 2 introduces progressive resistance and eccentric training to promote collagen remodeling and strengthening of the muscle-tendon unit. Phase 3 adds plyometric and sport-specific movements to rebuild tissue tolerance to high-speed, high-impact loading. Phase 4 uses quantified load monitoring (such as weekly training volume changes and acute:chronic workload ratio) to ensure a smooth return process and avoid recurrence from rushing. The entire process should be individualized, with regular tracking of outcomes using objective indicators (strength, jump tests, movement quality).

Preventive Training Strategies

The key to preventing athlete cardiac screening lies in two pillars: “managing training load” and “enhancing biomechanical resilience.” In terms of training load management, avoiding sudden spikes in weekly training volume is the foremost principle. Research generally recommends that weekly training volume increases should not exceed approximately 10%, and the acute:chronic workload ratio (ACWR) can be used to maintain a relatively safe range, balancing adaptation and risk control. Overtraining and inadequate recovery impair tissue repair capacity and are common upstream factors in many overuse injuries.

Building biomechanical resilience requires addressing the entire kinetic chain. The following are specific, evidence-based preventive exercise directions:

1. Proximal stabilization strengthening: Strengthening hip abductors, hip extensors, and trunk core muscles improves dynamic alignment and reduces compensatory loading, serving as a common foundation for preventing lower-extremity overuse injuries.
2. Eccentric and progressive resistance training: Eccentric loading has been shown to enhance tendon and muscle tolerance, and is particularly effective for preventing muscle and tendon pathologies.
3. Movement quality re-education: Improving running form (such as moderately increasing cadence and avoiding excessive stride length) and cycling posture (appropriate saddle and handlebar configuration) reduces peak loading per stride/revolution.
4. Flexibility and mobility maintenance: Dynamic stretching and mobility training for tight key muscle groups ensures smooth force transmission.
5. Progressive adaptation and periodization: Periodized training schedules with deload weeks allow adequate time for tissue repair and supercompensation.

It is worth emphasizing that prevention programs require adherence to be effective. Integrating preventive exercises into daily warm-ups or strength sessions and presenting them in a simple, executable format are practical keys to improving long-term compliance. Coaches and athletes should establish a culture of “listening to body signals,” treating minor discomfort as an early warning to adjust training rather than ignoring it or pushing through.

Local Application in Taiwan

Taiwan’s geography, climate, and race environment have unique influences on the occurrence and management of athlete cardiac screening. Climatically, Taiwan’s summer heat and humidity cause rapid core temperature elevation and high dehydration risk during exercise, leading to premature fatigue and decreased neuromuscular control, indirectly increasing the risk of cardiac injury. Local athletes are advised to train in the early morning or evening, pay attention to hydration and electrolytes, and proactively reduce training intensity and volume on hot days.

Regarding venues, urban athletes often train on riverside bike paths, PU tracks, and hard asphalt surfaces. Unidirectional loop tracks can cause uneven unilateral loading, so alternating directions is recommended; prolonged training on hard surfaces should be paired with appropriate footwear and gradually accumulated mileage. Taiwan’s mountainous terrain (such as Yangmingshan, Wuling, and Beihuang) offers abundant climbing and descending training opportunities, but long descents place extremely high eccentric loads on joints and tendons, requiring gradual progression and enhanced eccentric tolerance.

At the event level, Taiwan’s marathon, cycling (such as the Taiwan KOM Challenge), triathlon, and trail running events are密集, and the concentrated race season often leads athletes to compress recovery in pursuit of results. A complete periodized plan should be used to connect target events, with tapering before races and adequate recovery afterward. On the medical side, injury identification and triage capabilities at race venues should be strengthened to enable early intervention and prevent minor injuries from becoming chronic conditions. Overall, combining international evidence with Taiwan’s climate, terrain, and race rhythm is essential to developing prevention and rehabilitation programs truly suited to local athletes.

Common Myth-Busting

Myth 1: “You should rest completely until the pain is gone.” Complete rest may temporarily relieve symptoms, but it causes muscle loss and tissue deconditioning, which actually prolongs recovery and increases the recurrence rate. The correct approach is “relative rest” combined with progressive loading under pain monitoring, allowing tissues to receive appropriate stimulation and remodel within a tolerable range.

Myth 2: “Abnormal imaging findings mean the pathology is severe and must be treated.” A large body of research shows that asymptomatic individuals also frequently have abnormal imaging findings, and imaging does not necessarily correlate with symptoms. Treatment decisions should be based primarily on clinical symptoms and functional deficits, rather than imaging reports alone.

Myth 3: “Injections or anti-inflammatory medication can cure the problem.” Medications and injections are mostly symptom management and cannot replace exercise therapy that corrects loading and strengthens tissues. Over-reliance on passive treatments often leads to recurring problems.

Myth 4: “Just treat the painful area.” Overuse injuries are usually the end-stage manifestation of dysfunction across the entire kinetic chain. Treating only the symptom without correcting the upstream loading sources and control deficits makes recurrence likely. Comprehensive assessment and holistic intervention are the fundamental solutions.

Conclusion

Athlete’s heart screening is a typical multifactorial overuse injury. Its onset and recovery involve a complex interaction among training load, biomechanical alignment, neuromuscular control, tissue repair capacity, and psychosocial factors. The evidence reviewed in this article consistently points to one core message: exercise therapy centered on progressive loading is the safest and most effective intervention for the vast majority of overuse injuries, while passive treatments and invasive procedures should be used cautiously and sparingly.

For athletes in Taiwan, integrating international evidence with local climate, terrain, and race pacing to build long-term habits of “load management, biomechanical strengthening, and listening to body signals” is far more critical than making repairs after injury occurs. The best treatment for sports injuries is always prevention; and once injured, following scientific, staged rehabilitation based on objective indicators, with a gradual return to sport under professional guidance, is the true path to achieving the goal of “returning to sport without reinjury.” May every sports enthusiast, on the basis of understanding their own body, enjoy the joy of sport for the long term.

References

1. Corrado D et al. (2006). JAMA
2. Maron BJ et al. (2007). Circulation
3. Harmon KG et al. (2011). Br J Sports Med
4. Sharma S et al. (2017). NEJM

Related Reading

• Preventing Infection During the Post-Exercise Immune Window: An Integrative Study of Diet, Sleep, and Stress
• Psychosocial Predictors of Sports Injuries: Clinical Application of the Fear-Avoidance Model
• Molecular Mechanisms of Eccentric Training on Tendon Repair: A Study on Accelerated Collagen Synthesis
• Injury Patterns at Taiwan Marathon Medical Stations: A Statistical Analysis of 4-Year Data