Paediatric Cardiology for General Paediatricians Dr Talal Farha Consultant Paediatrician SpR Regional Teaching Taunton 22 Jan 2008

Essentials in looking at an ECG Rhythm (sinus….nonsinus) Rate, Atrial and ventricular rates. QRS axis, T axis, QRS-T angle Intervals: PR. QRS, and QT P wave amplitude and duration QRS amplitude and R/S ratio Q wave St- Segment and T wave abnormalities

ECG tips How do you determine Sinus rhythm? How do you determine Sinus rhythm? What is T axis? What is T axis? What is QRS/T angle? What is QRS/T angle?

Rhythm P before every QRS P before every QRS P axis (0-90). P inverted in aVR P axis (0-90). P inverted in aVR

P wave axis The location of the P-wave axis determines the origin of an atrial-derived rhythm: The location of the P-wave axis determines the origin of an atrial-derived rhythm:  0 to 90 degrees = a high right (normal sinus rhythm)  90 to 180 degrees = a high left  180 to 270 degrees = a low left  270 to 0 degrees = a low right

T wave In most leads, the T wave is positive. In most leads, the T wave is positive. A negative T wave is normal in lead aVR. A negative T wave is normal in lead aVR. Lead V1 may have a positive, negative, or biphasic T wave. In addition Lead V1 may have a positive, negative, or biphasic T wave. In addition It is not uncommon to have an isolated negative T wave in lead III, aVL, or aVF. It is not uncommon to have an isolated negative T wave in lead III, aVL, or aVF.

Inverted (or negative) T waves can be a sign of Coronary ischemia Coronary ischemia Left ventricular hypertrophy Left ventricular hypertrophy

T axis Determined by the same methods as QRS Determined by the same methods as QRS 0 to + 90 is normal 0 to + 90 is normal T Axis out side the normal quadrant could suggest conditions with Myocardial dysfunction. T Axis out side the normal quadrant could suggest conditions with Myocardial dysfunction.

QRS-T Angle Formed by the QRS axis and the T axis Formed by the QRS axis and the T axis QRS-T angle >60 degrees is unusual but if > 90 degrees, it is abnormal. QRS-T angle >60 degrees is unusual but if > 90 degrees, it is abnormal. Abnormally wide angle, with T axis outside the normal quadrant is seen in Abnormally wide angle, with T axis outside the normal quadrant is seen in - severe ventricular hypertrophy with starin - severe ventricular hypertrophy with starin - Ventricular conduction disturbances - Ventricular conduction disturbances - Myocardial dysfunction of a metabolic or ischemic nature. - Myocardial dysfunction of a metabolic or ischemic nature.

Top Tip For ECG Read more ECGs Read more ECGs

Do not forget, nothing replaces good traditional clinical examination and detailed history

Syncope How often related to the heart? How often related to the heart? What are the related cardiac conditions? What are the related cardiac conditions? How do we approach it? How do we approach it?

Definition Syncope is a transient loss of consciousness and muscle tone. Syncope is a transient loss of consciousness and muscle tone. Near syncope: Near syncope: premonitory signs and symptoms of imminent syncope occur; dizziness with or without blackout, pallor, diaphoresis, thready pulse and low BP premonitory signs and symptoms of imminent syncope occur; dizziness with or without blackout, pallor, diaphoresis, thready pulse and low BP

Cause Brain function depends on Oxygen and glucose. Brain function depends on Oxygen and glucose. Circulatory, metabolic, or neuropsychiatric causes. Circulatory, metabolic, or neuropsychiatric causes. Adults syncope mostly cardiac. Adults syncope mostly cardiac. Children’s mostly benign. Children’s mostly benign.

Causes of Syncope in Children Extra cardiac causes Extra cardiac causes Vasovagal Vasovagal Orthostatic Orthostatic Failure of systemic venous return Failure of systemic venous return Cerebrovascular occlusive disease Cerebrovascular occlusive disease Hyperventilation Hyperventilation Breath holding Breath holding Breath holding Breath holding

1- Vasovagal Syncope Neurocardiogenic Common Syncope Predrome for few seconds; dizziness, light-headedness, pallor, palpitation, nausea, hyperventilation then Loss of consciousness and muscle tone Predrome for few seconds; dizziness, light-headedness, pallor, palpitation, nausea, hyperventilation then Loss of consciousness and muscle tone Falls without injury Falls without injury Lasts about a minute, awake gradually Lasts about a minute, awake gradually

Vasovagal Syncope Anxiety Anxiety Fright Fright Pain Pain Blood Blood Fasting Fasting Hot and humid conditions Hot and humid conditions Crowded places Crowded places Prolonged motionless standing Prolonged motionless standing

Vasovagal Syncope Pathophysiology Standing posture without movement shifts blood to the lower extremities Standing posture without movement shifts blood to the lower extremities Decrease venous return, stroke volume, BP Decrease venous return, stroke volume, BP Less stretching of vent muscle and mechanoreceptors (mrcpts), decline in neural traffic form mrcpts, decreased arterial pressure, increase sympathetic output with Less stretching of vent muscle and mechanoreceptors (mrcpts), decline in neural traffic form mrcpts, decreased arterial pressure, increase sympathetic output with Higher HR, vasoconstriction (higher diastolic pressure) Higher HR, vasoconstriction (higher diastolic pressure)

Vasovagal Syncope Patients Decreased venous return produces large increase in ventricular contraction force Decreased venous return produces large increase in ventricular contraction force Activation of LV mechanoreceptors (normally only responds to stretch) Activation of LV mechanoreceptors (normally only responds to stretch) Increase neural traffic mimicking high BP condition Increase neural traffic mimicking high BP condition

Paradoxical withdrawal of sympathetic activity, vasodilatation, hypotension and bradycardia Paradoxical withdrawal of sympathetic activity, vasodilatation, hypotension and bradycardia Reduction of brain perfusion Reduction of brain perfusion

Diagnoses ECG, Holter, EEG, glucose tolerance test all are normally negative in V V E ECG, Holter, EEG, glucose tolerance test all are normally negative in V V E Tilt test Tilt test

Management Supine +/- feet up Supine +/- feet up Prevention Prevention Pseudoephedrine Pseudoephedrine Metoprolol Metoprolol Fludrocortisone Fludrocortisone Disopyramide Disopyramide Scopolamine Scopolamine

2- Orthostatic Hypotension What happen when we stand up? What happen when we stand up? HR, vasoconstriction HR, vasoconstriction Absent or inadequate upright position response, Hypotension without increased HR Absent or inadequate upright position response, Hypotension without increased HR

Diagnoses BP and HR supine and standing up. BP and HR supine and standing up. BP drop after 5-10 minutes up still by mmHG BP drop after 5-10 minutes up still by mmHG Positive tilt test without autonomic signs Positive tilt test without autonomic signs

Management Elastic stockings Elastic stockings High salt diet High salt diet Corticosteroids Corticosteroids Slow upright position Slow upright position

Micturition Syncope Rare form of orthostatic Rare form of orthostatic Rapid bladder decompression associated with degreased total peripheral vascular resistance. Rapid bladder decompression associated with degreased total peripheral vascular resistance.

3- Failure of systemic venous return Increased intrathoracic pressure Increased intrathoracic pressure Decreased venous tone (drugs; nitroglycerin) Decreased venous tone (drugs; nitroglycerin) Decreased volume (bleed…) Decreased volume (bleed…)

4- Cerebrovascular occlusive disease Mainly adult Mainly adult

Cardiac causes of Syncope Structural heart disease Structural heart disease Arrhythmia Arrhythmia

Why Cardiac ? Syncope at rest Syncope at rest Provoked by exercise Provoked by exercise Chest pain Chest pain Heart disease Heart disease FH of sudden death FH of sudden death

What Cardiac Obstructive lesions Obstructive lesions Myocardial dysfunction Myocardial dysfunction Arrhythmias Arrhythmias

Obstructive lesions AS, PS, HOCM, PHTX AS, PS, HOCM, PHTX Precipitated by exercise, no increase in cardiac output to accommodate increased demand. Precipitated by exercise, no increase in cardiac output to accommodate increased demand. Examination, CXR, ECG, Echo

Myocardial Dysfunction Ischemia, infarction secondary to CHD, Kawasaki’s.. Ischemia, infarction secondary to CHD, Kawasaki’s.. Myocarditis Myocarditis

Arrhythmia

Long QT Syncope, seizures, palpitation during exercise or with emotion Syncope, seizures, palpitation during exercise or with emotion ECG ECG Ventricular arrhythmias (Tachy) with risk of sudden death Ventricular arrhythmias (Tachy) with risk of sudden death

clinically FH 60% FH 60% Deafness 5% Deafness 5% Presentation with Syncope 26%, seizure 10%, cardiac arrest 9%, presyncope palpitation 6% Presentation with Syncope 26%, seizure 10%, cardiac arrest 9%, presyncope palpitation 6% Symptoms during exercise or emotion Symptoms during exercise or emotion Normally symptoms related to ventricular arrhythmias, mostly end of second decade of life. Normally symptoms related to ventricular arrhythmias, mostly end of second decade of life.

Syncope in adrenergic arousal, exercise (swimming is a particular trigger) Syncope in adrenergic arousal, exercise (swimming is a particular trigger) Abrupt noises (Alarm, doorbell, phone..) Abrupt noises (Alarm, doorbell, phone..)

Tests ECG with QTc >0.46 seconds ECG with QTc >0.46 seconds Frequently finding abnormal T wave Frequently finding abnormal T wave Bradycardia (20%) Bradycardia (20%) Exercise test, maximum prolongation after 2 minutes of recovery, ventricular arrhythmia in 30% during exercise Exercise test, maximum prolongation after 2 minutes of recovery, ventricular arrhythmia in 30% during exercise Holter monitoring may show longer QTc Holter monitoring may show longer QTc

Diagnoses Criteria Electrophysiological society Electrophysiological society - QTc >0.44 with no other causes (0.46 sec) - Positive family history plus unexplained syncope, seizure or cardiac arrest proceeded by trigger such as exercise, emotion

Treatment Discuss with cardiologist Discuss with cardiologist Avoid drugs associated with long QT Avoid drugs associated with long QT Avoid swimming, competitive sports Avoid swimming, competitive sports Beta blockers Beta blockers Demand cardiac pacing (Pacemaker and defib) Demand cardiac pacing (Pacemaker and defib) Left cardiac sympathetic denervation Left cardiac sympathetic denervation

Prognoses Untreated 75-80% mortality Untreated 75-80% mortality Beta blockers reduce mortality to some extent Beta blockers reduce mortality to some extent The adjusted annual mortality rate on treatment is 4.5% (10 year mortality of 50%) The adjusted annual mortality rate on treatment is 4.5% (10 year mortality of 50%)

Advise related to CHD If one child has CHD, what are the chances of the second? If one child has CHD, what are the chances of the second? One parent has CHD, can offspring be affected? What are the chances? One parent has CHD, can offspring be affected? What are the chances? See Handouts, statistical list of potential risks See Handouts, statistical list of potential risks

Pathophysiology of congenital heart lesions

Pathophysiology of left to right shunt lesions ASD

Pathophysiology of left to right shunt lesions VSD

Pathophysiology of left to right shunt lesions PDA

Pathophysiology of left to right shunt lesions AVSD

Pathophysiology of Obstructive and valvular regurgitation lesions MR

Pathophysiology of Obstructive and valvular regurgitation lesions AR

Pathophysiology of Obstructive and valvular regurgitation lesions PR

Pathophysiology Cyanotic lesions TGA with good mixing RV 80% LV 90% 65% LA 90%

Pathophysiology TGA with poor mixing RV 45% LV 92% 100%30% LA 92% 45%

Pathophysiology TGA with poor mixing RV 45% LV 92% 100%30% LA 92% 45%

Tips Read ECGs, easy to loose ECG skills. Read ECGs, easy to loose ECG skills. Ask for help Ask for help As all specialties, it is only common sense. As all specialties, it is only common sense.