The spectrum of cardiac issues in adolescence is very different than in adulthood. A cardiac cause of chest pain is rare.

Dr Michael Davis, Cardiologist, Perth

Common causes include costochondritis, injury, stress or anxiety, precordial catch syndrome or acid reflux. Pericarditis causes sharp, pleuritic, and mid-sternal pain possibly radiating to the shoulders and is often alleviated by sitting or leaning forward. Cough, dyspnoea, and fever are common. Ectopics sometimes cause momentary chest discomfort and rapid SVT can cause ischemic pain or even a troponin rise. 

Typical exertional angina might suggest a coronary artery anomaly and warrants referral. Isolated dyspnoea is rarely cardiac. Most significant murmurs are identified in childhood. A new or previously unidentified murmur is most likely innocent but consider rheumatic heart disease or hypertrophic cardiomyopathy. Echocardiography is the appropriate first step.

Presyncope and syncope

More than 90% of fainting in adolescents is vasovagal, usually diagnosed on history from precipitants and warning symptoms. Orthostatic presyncope or syncope most commonly occurs in adolescents who are salt deficient, sometimes due to overzealous parenting with low salt diets imposed on their physically active offspring. Both these causes of dizziness/fainting can usually be treated with significantly increased salt intake and recognition of symptoms (sitting or lying down if they feel dizzy). 

Most serious causes of syncope include arrhythmias related to abnormal atrioventricular pathways (e.g., WPW), cardiac ion channelopathies (e.g., long QT syndrome) or underlying structural heart disease.

Eating disorders can be associated with a variety of cardiac issues, the most worrying being sudden death resulting from arrhythmia. The QT interval on the ECG can prolong, related to quick or severe weight loss and hypokalaemia/hypomagnesemia (especially with purging or laxative abuse), and occasionally to cardiac myofibrillar degeneration or even heart failure. 

Medications, especially psychotropic drugs, can also prolong the QT. A long QT predisposes to polymorphic VT (“torsade de pointes”), which can degenerate to VF. The 12-lead ECG needs to be monitored closely in anorexia nervosa. 

Cardiology referral is indicated when syncope occurs in certain circumstances: during exercise; without warning (no preceding dizziness, muffled hearing, or visual changes); with severe injury; with family history of sudden unexplained death (or drowning, MVA), cardiomyopathy or congenital heart disease; with an eating disorder, when cardiac examination (murmur) or ECG (always perform) abnormal.

Palpitation

Some adolescents are aware of rapid heart beating due to normal sinus tachycardia with stress or exercise. Inappropriate sinus tachycardia, as the names suggests, is a sinus rate excessive for the body’s needs and demands exclusion of cardiac conditions (such as heart failure) or systemic conditions (such as fever, anaemia, thyrotoxicosis) where the rate is appropriate. This rare condition responds well to ivabradine.

Ectopics are uncommon in adolescents and generally benign and require reassurance. If associated with symptoms of concern such as rapid palpitation, presyncope/syncope or shortness of breath, then ECG, Holter and echocardiogram.

Postural orthostatic tachycardia syndrome (POTS) is a chronic condition involving the autonomic nervous system characterised by orthostatic intolerance and often beginning after a viral infection, surgery, trauma or pregnancy.

Under the age 19, it is characterised by an increase in heart rate going from lying to standing for 10 minutes of over 40bpm. There are numerous associated symptoms including palpitation and dizziness, “brain fog”, chronic fatigue, sleep disturbance, headache, and gastrointestinal symptoms. 

Most with POTS have self-diagnosed from chat groups and do not have the condition. As well as the characteristic postural heart rate increase, this is a diagnosis of exclusion. Treatment is similar to orthostatic hypotension with salt supplementation and a variety of medications including fludrocortisone, midodrine and ivabradine. The prognosis is favourable with symptoms generally improving in two to five years.

Rapid palpitation with sudden onset and offset strongly suggests paroxysmal supraventricular tachycardia. A 12-lead ECG is essential, and documentation of rhythm with ambulatory ECG monitoring (including devices such as the Kardia or Apple Watch) invaluable. 

The patient needs to be taught vagal manoeuvres to terminate episodes (especially Valsalva, gag, iced water to the face). If the ECG shows ventricular pre-excitation (WPW pattern) or symptoms are severe or troublesome then referral to a cardiac electrophysiologist is indicated. For this and other types of SVT, catheter ablation may be indicated and be curative.

The athlete

Because of the belief that sports deaths should be preventable, cardiac screening programs are widespread, but guidelines differ. Screening includes history and family history, examination, ECG, sometimes echocardiography and even cardiac MRI! The Australian College of Sports and Exercise Physicians recommends screening only elite athletes, with history, examination and resting 12-lead ECG every second year from ages 16 to 25. 

A recent study followed over 11,000 15- to 17-year-old, mostly male, English soccer players who underwent screening including ECG and echocardiogram, identifying 42 (0.38%) with cardiac issues capable of causing sudden death, the majority with WPW (n = 26; 62%). Only two of the 42 had symptoms; 36 had an abnormal ECG and 12 had abnormalities on echo. Significant heart disease not typically associated with sudden death (e.g., valvular disease or septal defects) was found in 225 (2%).

During the 20-year study period, 23 adolescents died, eight from a cardiac cause (with autopsy), seven had cardiomyopathy (six had normal cardiovascular screens)! The overall incidence of sudden death was around 1 in 14,800 person-years. The estimated cost of screening plus follow-up of those 830 with abnormal findings was over AU $8 million. 

On top of the financial costs of screening are the psychological and health impact of false positive results. The cost of screening might be better spent on widening the availability of automated external defibrillators and CPR education for adults supervising junior sport. Examples of extremely high successful resuscitation rates have been described in Japan during marathons (with an astonishing 100% survival rate) and in Italy during competitive sport (with a 93% survival rate).

Common normal adolescent ECG variations
  • Pronounced sinus arrhythmia
  • Short sinus pauses < 1.8 seconds
  • First degree atrioventricular block
  • Mobitz type 1 second degree atrioventricular block (Wenckebach)
  • Junctional rhythm
  • Isolated ventricular or supraventricular ectopics
  • Partial RBBB (rSr V1)
  • T wave inversion in V2 (even V3, V4)
  • Large precordial QRS voltages.
Key messages
  • Syncope usually benign, but ECG always and watch for red flags
  • Palpitations are common and usually benign. ECG.
  • There are particular considerations for athletes and those with eating disorders.

Author competing interests – nil