You are approached by one of the adult congenital specialist nurses for advice regarding a patient with tetralogy of Fallot (ToF) who has contacted them directly. The patient, who is now 24 years old, had total surgical repair in childhood and has remained well since, but has recently been experiencing palpitations with associated presyncope. The symptoms are transient and there has been no syncope. There are no other relevant symptoms or reduction in exercise capacity. The echocardiogram from clinic a year previously showed moderate–severe PR and moderate RV dilatation. The nurse has performed an ECG which shows SR with first-degree AV block and RBBB (QRS 190 ms).
What is the most appropriate advice?
The duration of the QRS is proportional to the size of the RV. It has been shown that a QRS >180 ms is a highly sensitive marker for VT and SCD in previous ToF repair (SCD accounts for a third of late deaths). This patient’s case should be urgently discussed and the option of an ICD considered. Haemodynamic assessment with echocardiography is also important as the PR or RV dilatation may have progressed, with the need for PV intervention. Non-sustained VT is common but is not an indicator of SCD risk. Antiarrhythmics are not indicated if the patient is asymptomatic. The VT is normally of RVOT origin (infundibulectomy or VSD patch). Development of major arrhythmias (AF/flutter and sustained VT) normally reflects haemodynamic deterioration (PR, RV dilatation) and therefore haemodynamic assessment and correction of the lesion can correct the arrhythmia (with the option of surgical/catheter ablation).
One of the stroke physicians asks your advice regarding a 45-year-old man admitted with a stroke. The patient is overweight with known hypertension and raised lipids. He is a non-smoker. Carotid Doppler scans show no atheroma. The stroke physicians have performed a 24-hour tape which has shown clear runs of asymptomatic paroxysmal AF. They have also requested a bubble contrast echo which has demonstrated complete opacification of the left heart with Valsalva release. The heart is structurally normal apart from moderate LVH and a left atrial area of 30 cm2 . The patient is currently on antiplatelet therapy, but they are keen to know what the immediate strategy would be from the cardiac point of view.
This case describes a relatively young patient with a number of risk factors for stroke. Despite having risk factors for atherosclerosis, because of his age (and clear carotid Doppler scans) other foci for embolic stroke have been pursued. Two possibilities have been identified: left atrial thrombus as a result of AF or a paradoxical embolus via the PFO. The question asks for the immediate strategy. Anticoagulation protects against both sources of embolus and so is the immediate treatment of choice. PFO closure will not protect against LA thrombus due to PAF and anticoagulation would still be required. Complex ablation and device treatment may be a future option based on progress, but needs careful discussion. TOE is not required after a suggestive positive bubble test, which is the preferred modality to confirm a PFO. Periprocedural TOE is used to guide transcatheter closure. The AF is likely to be due to uncontrolled hypertension (LVH) and strict control with an ACE inhibitor can reduce the AF burden.
One of the medical students asks you what a Fontan operation consists of.
What is your answer?
You are following up a 33-year-old male in clinic who was referred by the GP for increasing breathlessness and intermittent palpitations. A transthoracic echocardiogram was performed which revealed moderate right heart dilatation but no abnormality of the right-sided valves. Right ventricular systolic pressure was estimated at 30 mmHg. He has no respiratory problems and is a lifelong non-smoker. He is slim with good echocardiogram images, and careful interrogation of the intra-atrial and ventricular septum shows no evidence of a colour flow.
What is a likely differential diagnosis?
Secundum and primum (AVSD) defects can be clearly seen on transthoracic echo. However, sinus venosus defects may not be seen. This patient has signs and a suspicion of an ASD physiology type left-to-right shunt. This includes anomalous pulmonary venous drainage, which is associated with superior sinus venosus ASD. He should have further imaging in the form of TOE or CT/CMR to identify the pulmonary venous drainage and look for a less obvious ASD. PFOs cause no haemodynamic anatomical change. Haemodynamically significant VSDs result in left ventricular volume loading and increased pulmonary flow with eventual pulmonary hypertension, as do PDAs (not right-sided volume loading).
You are following up a 28-year-old male in clinic who was referred by his GP for increasing breathlessness and intermittent palpitations. He has come back for the result of his TOE which has shown evidence of a superior sinus venosus ASD with normal pulmonary venous drainage and moderate right heart dilatation.
He asks you about the likely treatment.
This patient has a sinus venosus ASD with symptoms and evidence of haemodynamic anatomical change. The defect is in the superior atrium at the entrance of the SVC into the RA (almost as if the SVC overrides the atrial septum). Currently, transcatheter solutions are not available and surgery is the treatment of choice. Sinus venosus ASDs are often associated with anomalous pulmonary venous drainage which requires surgical correction. If the shunt is not corrected, this may result in irreversible right heart dysfunction, pulmonary hypertension (late), or the development of atrial arrhythmias such as AF which complicate the situation. ACE inhibitors reduce LA pressure, and therefore in theory can reduce the shunt, but this is not a suitable treatment.
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