Cardiology Flashcards
The electrocardiogram (ECG) of an asymptomatic four-year-old girl who presented with a systolic murmur is illustrated above. She was acyanotic. Precordial examination revealed a single loud second heart sound and a soft systolic ejection murmur at the left sternal edge. Which one of the following is the most likely diagnosis?
ECG features: abnormal Q waves in leads III, aVR, aVF, V1 and V2
Single loud S2 due to abnormal position of aortic and pulmonary arteries
Truncus arteriosus
Tricuspid atresia
Hypoplastic left heart syndrome
Transposition of great arteries
L-Transposition of great arteries
Tetralogy of Fallot
Single loud S2 due to abnormal aortic or pulmonary valves
Severe aortic or pulmonary stenosis
Pulmonary atresia
Eisenmenger syndrome
Large VSD
The S2 is loud in patients with L-TGA because of the anterior position of the aortic valve. In addition to atrioventricular conduction disturbances, the ECG may show abnormal P waves; absent Q waves in V6; abnormally present Q waves in leads III, aVR, aVF, and V1; and upright T waves across the precordium.
In this patient, the presence of Q waves over the right precordium (because of reverse septal depolarisation) with absent Q waves over the lateral precordium in the the absence of other criteria for right ventricular hypertrophy, should suggest L-TGA
A 12-year-old boy is seen in the Emergency Department with a history of a few seconds of lightheadedness while walking in the hot sun. He was then observed to fall to the ground and was unresponsive for one minute. There is no history of chest pain, shortness of breath or palpitations.
ECG showed a delta wave with a short PR. Therefore it is Wolff-Parkinson-White.
In WPW, pre-excitation occurs because of conduction of an atrial impulse not by means of the normal conduction system, but via an extra atrioventricular muscular connection (an accessory pathway), that bypasses the AV node.
A four-week-old infant presents with tachypnoea and failure to thrive. On examination the infant has a respiratory rate of 60/minute with subcostal recession. The pulses are full and the liver is palpable 4 cm below the right costal margin. The praecordium is active. On auscultation there is an audible ejection click and a non-specific systolic ejection murmur is noted at both upper sternal edges. The infant’s oxygen saturation in room air is 93%. Which one of the following is the most likely diagnosis?
4 week old with failure to thrive, mildly reduced oxygen saturations, signs and symptoms of congestive cardiac failure, an active praecordium, an ejection click and a non-specific systolic murmur. All these features are consistent with truncus arteriosus, in which a single arterial trunk arises from the heart, typically over-riding a VSD so that the truncus receives blood from both the RV and LV. It occurs in approximately 10 of 100 000 live births and represents 1-2% of congenital heart defects. Variations of the CATCH-22 syndrome are seen in about a third of cases.
One of the most commonly cited classification systems includes types I-IV, based on where the pulmonary arteries arise from the common trunk;
I - origin of a single pulmonary trunk from the left lateral aspect of the common trunk.
II - separate origins of the left and right pulmonary arteries from the posterolateral trunk.
III - separate arteries originate from the lateral aspect of the trunk or aortic arch.
IV - neither pulmonary artery arises from the trunk. Instead, the pulmonary circulation is supplied by hypertrophied bronchial arteries arising from the descending aorta. This in now thought to represent a form of pulmonary atresia with VSD rather than a variant of truncus.
The pathophysiology of truncus is characterised by left to right shunting with over-circulation of the pulmonary circuit (especially as PVR decreases in early infancy), CCF, right heart failure and mild cyanosis. Over time, Eisenmenger physiology may evolve as pulmonary hypertension ensues. The truncal valve has between 2 and 6 cusps, and displays varying degrees of incompetence. Symptoms arise in early infancy, consisting of poor feeding, failure to thrive and, tachyponea and mild cyanosis. Typical examination findings are a wide pulse pressure, active praecordium, a loud and single 2nd heart sound, early ejection click, an ESM loudest LSE +/- thrill, and possibly a high-pitched early diastolic decrescendo murmur at the MLSE. Surgical correction is required before the age of 4 weeks before pulmonary hypertension develops. Anti-failure medications may be instigated pending surgery. Surgical correction involves complete primary repair, with closure of the VSD, channelling of the LV outflow into the truncus +/- truncal valve repair and formation of a communication between the RV and pulmonary arteries via a homograft conduit (Rastelli repair). This conduit is replaced as the child grows.
The fact that the child is symptomatic in the neonatal period, has evidence of CCF, failure to thrive, mild cyanosis, and characteristic findings on auscultation, makes truncus arteriosus the most likely underlying pathology.
What cardiac structure is most likely to be affected in chronic rheumatic heart disease?
Acute rheumatic heart disease often produces a pancarditis characterised by endocarditis, myocarditis, and pericarditis. Endocarditis is manifested as valve insufficiency. Endocarditis is a universal finding in rheumatic carditis whereas the presence of pericarditis and myocarditis is variable.
Most cases consist of either isolated mitral valvular disease or combined aortic and mitral valvular disease. The mitral valve is most commonly and severely affected (65-70% of patients), and the aortic valve is second in frequency (25%).
The tricuspid valve is deformed in only 10% of patients and almost always is associated with mitral and aortic lesions.
The pulmonary valve is rarely affected. Isolated aortic or right sided valvular involvement is uncommon
Widened splitting of the pulmonary and aortic components of the second heart sound during expiration is an auscultatory feature of:
normal physiology, splitting of the second heart sound is increased during inspiration. During inspiration, negative intrathoracic pressure causes increased venous return to the right heart, with increased right ventricular filling and therefore a relative delay in closing of the pulmonary valve after systole.
Mild-moderate AS produces normal splitting of S2. In severe AS the intensity of aortic valve closure is diminished. In children paradoxically (rarely) you can get splitting of S2 in expiration with severe AS.
Wide splitting of S2 occurs in: ASD, PS, Ebstein anomaly, TAPVR, RBBB.
Single S2 occurs in: pulmonary or aortic atresia, severe stenosis, truncus arteriosus, TGA.
A six-month-old child with cardiac failure secondary to severe dilated cardiomyopathy is initially treated with Frusemide and Spironolactone. The addition of which of the following drugs to the child’s medical therapy is most likely to result in hyperkalaemia if no changes are made to the existing therapy?
Captopril: ACE inhibitors induce a state of hypoaldosteronism and also impair renal potassium excretion by reducing the effective glomerular filtration rate in patients with volume depletion, renal artery stenosis, or chronic renal insufficiency. In these patients, ACE inhibitors blunt the postglomerular arteriolar constriction induced by angiotensin-II, leading to a reduction in the delivery of sodium and water to the distal nephron, which, in combination with hypoaldosteronism, may promote hyperkalemia.
Widened splitting of the pulmonary and aortic components of the second heart sound during expiration is an auscultatory feature of:
Mild-moderate AS produces normal splitting of S2. In severe AS the intensity of aortic valve closure is diminished. In children paradoxically (rarely) you can get splitting of S2 in expiration with severe AS.
4 week old with prolonged jaundice. Acyanotic and normal volume peripheral pulses. Deep set eyes and triangular shaped face. CXR shows butterfly vertebrae. Systolic murmur
Alagille syndrome caused by mutations in JAG1 or NOTCH 2 proteins. Results in cholestasis due to paucity of interlobular bile ducts. Associated with congenital heart disease especially peripheral pulmonary stenosis (others TOF, septal defects, coarctation of aorta).
Other clinical features include butterfly vertebrae, posterior embryotoxin, dysmorphic facies (broad nasal bridge, deep-set eyes, triangular faces) and renal dysplasia.
Six-year-old boy presenting to general paediatrics outpatient department for review. Although he has moderate intellectual impairment, his speech and language skills are age-appropriate. He has a history of intermittent constipation. On examination, he is noted to have hypertelorism, stellate iris, thick vermillion border and long philtrum as well as a systolic murmur.
Williams syndrome. Caused by a micro-deletion at chromosome 7q11.23, which includes the elastin gene. Common clinical features include supravalvular aortic stenosis (70% of cases), pulmonary valve stenosis, renal artery stenosis, constipation and hypercalcaemia. Typical facial features described as ‘elvin facies’ and include stellate iris, wide mouth, widely spaced teeth, thick vermillion border, hypertelorism, long philtrum and small jaw. Mild-moderate intellectual impairment is common with age-appropriate language skills. People with Williams syndrome are also often described as being highly social.
5-day-old male neonate admitted to the Neonatal Intensive Care Unit following surgical repair of imperforate anus noted at delivery. He was also noted to have a single umbilical artery and renal USS revealed right-sided renal aplasia. On exam he was noted to have polydactyly and a systolic heart murmur with normal pre and post-ductal oxygen saturation.
This boy has VACTERL association. This is a collection of associated congenital anomalies without as yet a known cause (hence association not syndrome). The anomalies can be grouped together by the acronym VACTERL:
Vertebral abnormalities – missing vertebrae, butterfly vertebrae, hemi-vertebrae, missing ribs, supranumerary ribs, scoliosis, absent coxcyx.
Anal atresia – may coexist with abnormalities in the lower urogenital tract.
Cardiac defects – most commonly associated with VSD however ASD, hypoplastic left heart, transposition of the great arteries and tetralogy of Fallot also occur.
Tracheoesophageal fistula +/- oesophageal atresia
Renal abnormalities – single umbilical artery, renal aplasia or dysplasia, ectopic kidney, vesicoureteric reflux, hydronephrosis and hypospadias.
Limb abnormalities – radial aplasia, radial hypoplasia, triphalangeal thumb, polydactyly, syndactyly, clubfoot, hypoplasia of the great toe/tibia.
