Category Archives: Cardiology

POTS

POTS (Postural orthostatic tachycardia syndrome) – more common in females. 

Orthostatic tachycardia (NOT hypotension, which suggests vasovagal syncope), dizziness, chest pain, palpitations, headaches, dyspnoea.  Sometimes bluish red discolouration in lower limbs. 

No known cause, can have sudden onset in previously fit individuals.  Associated with Ehlers Danlos (venous return problem?). 

Can be debilitating, associated with chronic pain, sleep problems, GI symptoms.  Can improve over time.  Diagnosis – heart rate increases by 30 beats per minute (bpm) or more (40bpm in those aged 12-19) within 10 minutes of standing, or if it increases to more than 120bpm. “Hyperadrenergic” POTS is where BP actually goes up, rather than down.

Monitor during valsalva manoeuvre to look for autonomic dysfunction.

Increase fluid intake to 2-3L daily. Increase salt intake?

Waist high compression stockings?

Consider treatment with beta blocker, fludrocortisone, desmopressin, clonidine, modafinil, SSRI.

Arrhythmia

See SVT.

Adenosine 150mcg/kg? 12yr 3mg

Broad complex SVT – just treat as VT.

Cardioversion

Remove oxygen tubing for shocks unless closed circuit.

Stand clear – look at top/middle/bottom!

IM/IN ketamine plus sedation for synchronised shock.

Synchronised shocks are 1 then 2 J/kg.

Sync button needs pressed for each shock – most machines immediately reset. Press and hold – needs time to sync and give shock.

Chest pain

Common in children esp teenagers, often at rest, sharp but brief. Extremely rare to find a cause…

Differential:

  • Oesophagitis
  • Asthma
  • Pulmonary embolism
  • Tachyarrhythmia – but you would expect palpitations and colour change, “on/off”
  • Precordial catch syndrome
  • Costochondritis (Tietze syndrome)
  • Catecholamine secreting tumours??
  • Cardiomyopathy? Ischaemic cardiomyopathy eg anomalous origin of left coronary artery (from pulmonary artery) – but in kids, either too young to describe pain (infants) or else too mild to present with angina (instead present with failure).  Arrhythmogenic ventricular cardiomyopathy (usually right, but biventricular involvement recognised) can present with pain but usually syncopal episodes.  [Circulation. 2019;140:e9–e68]
  • Fabry’s as cause of bizarre pain (heart involvement but pain usually GI). 
  • Aortic root problem – as seen in Marfan’s and other connective tissue problems.

So red flags would be syncope, colour change, sudden dizziness/confusion, sweating/clamminess suggesting cardiovascular compromise.

Assuming normal physical examination, and no family history of inherited cardiac problems (or sudden death), if not exertional then can be reassured. Pain killers not usually helpful as pain settles so quickly.

If exertional then needs ECG. Unlikely to be significant cardiac problem if normal.

[Archives 2014]

SVT

Supraventricular tachycardia – where abnormal rhythm initiated above atrioventricular node, so narrow complex (with normal conduction down bundles of His). Typically rate over 220, with abrupt onset (can be inferred from history).

ECG showing SVT and effect of adenosine
SVT showing effect of adenosine

Accessory pathway that bypasses the AVN is the usual reason, esp infants, but nodal reentrants quite common in older kids. Get a 12 lead before doing anything, unless absolutely impossible.

An accessory pathway usually has a delta wave (upsloping PR). If retrograde conduction, then inverted P wave seen immediately after the QRS. If a nodal reentrant, P wave is subsumed into QRS complex.

If decompensated then synchronised cardioversion (under IM/IN ketamine).

Vagal manoeuvres do work, such as doing a valsalva manoeuvre (get child to blow through straw!), bag of icy water held to face (count to 5). Older kids can stand on their hands! Carotid sinus massage is the least effective.

But best to go straight to IV adenosine if access available. Adenosine causes sinus arrest, which feels terrifying for child. Within a few seconds, wears off and spontaneous return of rhythm, hopefully a normal one. Can also induce wheeze. Give in antecubital fossa, so as close to heart as possible.

Starting dose lower if over 1yr. Then increase by 50-100mcg/kg each time. If adenosine doesn’t work:

  • check max dose (different for neonates and older children, 12mg max)
  • check rapid bolus and flush
  • check diagnosis is correct.

Digoxin is good for babies and infants but needs 2 loading doses 6 hours apart, and you may not get a result until then. Propanolol is contraindicated in asthma. Amiodarone should be used before 3rd shock. Verapamil is contraindicated under 1 year as can cause arrest.

Prognosis

SVT usually settles down by 6-12 months but may recur around the age of 8yrs. Onset outside infancy will probably not resolve spontaneously. Prevention needs to be discussed: some families will be happy just treating episodes as they occur. Otherwise use digoxin in infancy to prevent, propanolol later.

Rare forms

Rare forms:

  • Permanent form of Junctional Reciprocating Tachycardia (PFJRT) – chronic SVT, so may go unrecognised and then cause cardiomyopathy. The accessory pathway is resistant to DC shock and adenosine. Inverted P wave seen.
  • Ectopic atrial tachycardia – due to an ectopic focus. May also be chronic. Demonstrates warm up and slow down in rate, whereas others tend to have fixed rate. First degree block seen. Resistant to DC shock and adenosine.
  • Atrial flutter usually seen only in congenital heart disease but does occur in neonates with normal hearts! In which case it tends not to recur. Ventricular rate divides neatly into 300.
  • Atrial fibrillation – needs anticoagulation before DC conversion so control rate first with digoxin while loading warfarin.

Fabry’s disease

Alpha-galactosidase defect, one of the lysosomal storage disorders, with accumulation in various tissues.

X-linked but females get disease, so not correct to call them carriers.

Classically, “pain attacks”, affecting the extremities. In the abdomen, can mimic appendicitis. Due to accumulation in nerves. Since nothing to really see on examination, easily misdiagnosed as functional.

Other features:

  • Renal impairment and failure.
  • Angiokeratomas – a more specific feature, but not always present, and seen in other lysosomal disorders.
  • Corneal changes
  • Cerebrovascular and cardiac problems

[Omim]

Hypertension

In children under 10, high BP is usually secondary to an underlying disease or condition. Primary hypertension increasingly recognised in older, obese children.

Do repeated measurements, ideally automated home BP monitoring, before diagnosing hypertension. Check manually as well as with automated device. Beware “white coat effect”, even if not clearly anxious.

Use appropriate cuff size – cuff should cover at least 75% of the upper arm from the acromion to the olecranon (should be sufficient space at the antecubital fossa to apply stethoscope!) .  An inappropriately small cuff will overestimate BP.

Long list of causes, so follow the clues.

Family history important, of course.

Examination

So needs thorough history and examination, including:

  • Fundi
  • Bruits, radiofemoral delay
  • Neck for goitre

Complications

Consider then end organ effects –

  • Proteinuria, high creatinine
  • Retinopathy
  • Left ventricular hypertrophy, cardiac failure
  • Abnormal tone and reflexes, cranial nerve deficits if severe

Management

Depends on how high, whether other risk factors (diabetes, chronic kidney disease), symptoms and evidence of end organ damage.

Initially low salt diet, weight loss (if obese).  Remember other morbidities related to obesity.

Acute hypertension might need frusomide and/or nifedipine.

Long term treatment is only going to be started if no improvement with lifestyle measures. Target BP depends on risk factors, as above.

[2016 European Society for Hypertension guidelines]

Cardiomyopathy

Uncommon, but often tricky to recognise, potentially lethal.

Multiple causes:

  • Viral esp enterovirus
  • Genetic
  • Metabolic
  • Autoimmune
  • Chagas, Diphtheria important in other countries

Presents with anorexia, vomiting, breathlessness. Can be abdo pain (gut ischaemia?). Chest pain unusual, young children may struggle to describe anyway. Syncope or palpitations if arrhythmia. Confusion and agitation if acidotic.

Heart will eventually enlarge but may not be apparent initially. Inappropriate tachycardia; breathlessness with clear lungs and CXR (not always acidosis), esp with exertion. Hypotension.

May be new murmur eg MR if heart enlarged.

Small complexes, ST changes, q waves on ECG. Troponins may be high, LFTs deranged, renal impairment as secondary effects.

Echo diagnostic.

Start inotropes (peripheral possible). Various mechanical aids eg Berlin Heart, ECMO.

Alagille Syndrome

Autosomal dominant condition (70% sporadic) with characteristic facies, biliary hypoplasia, vertebral and cardiac abnormalities. JAG1 gene.

Paucity of intrahepatic bile ducts so typically prolonged jaundice, but depending on how many ducts, may not be obvious in first few months. Jaundice gradually improves, but only minority clear completely. 30% progress to cirrhosis.

Posterior embryotoxon (white ring at periphery of cornea) is a clue, but seen in 10% of normal population so not specific.

Cardiac includes pulmonary stenosis, Tetralogy of Fallot.

Facies: broad forehead, triangular face, deepset eyes, long nose with bulbous tip.

Butterfly vertebrae characteristic (asymptomatic – see on chest x-ray).

Other:

  • Renal Tubular Acidosis, renal cysts
  • Growth failure
  • Pancreatic insufficiency

Murmurs

An added sound heard when listening with a stethoscope, distinct from heart sounds or other clicks or snaps.

Can indicate a structural abnormality.  But can be heard in normal hearts too, esp kids.

Still’s murmur

Or “innocent” murmur.  Characteristic vibratory, crescendo-decrescendo sound, loudest along left sternal border.  Never louder than grade 3.  Typically gets quieter when child stands up (you would not expect a murmur caused by a structural abnormality to change).

Venous hum

Another innocent one, a rumble heard in the upper chest, disappears when lying down, or when neck turned or neck veins occluded gently.

Pulmonary flow murmur

Pulmonary valve closest to anterior chest wall, which might explain why you sometimes hear this.  Might be confused with pulmonary stenosis or subaortic membrane.

Prolonged QT interval

An abnormal finding on ECG.

QT interval changes with heart rate, so usually calculated as corrected QT (QTc), where average QT is divided by square root of RR interval (ie 1 second, if heart rate 60).

Associated with dysrhythmia, especially torsades de pointes (polymorphic ventricular tachycardia).

Seen with:

  • Genetic predisposition – Long QT syndrome
  • Certain drugs – antipsychotics (eg chlorpromazine, quetiapine), antiarrhythmics (!?), tricyclic antidepressants (eg amitriptyline), other antidepressants (eg citalopram, venlafaxine), antihistamines (terfenadine, but also loratadine, diphenhydramine, astemizole), macrolides, quinine.