New Heart Conditions in Adults With Congenital Heart Disease
New Heart Conditions in Adults With Congenital Heart Disease
Arrhythmias are a major cause of morbidity, hospitalisations and mortality in ACHD patients. Bradyarrhythmias caused by sinus node dysfunction or atrioventricular conduction abnormalities are frequently encountered as well as atrial or ventricular tachyarrhythmias. The causative factors are multifactorial and include scar tissue due to previous cardiac surgeries, inherent structural abnormalities and acquired comorbidities. Accordingly, arrhythmias are often precipitated by haemodynamic deterioration and systolic dysfunction. It has recently been recognised that diastolic dysfunction in patients without congenital heart disease is associated with atrial arrhythmias, especially atrial fibrillation. Risk factors for diastolic dysfunction include age, arterial hypertension, obesity and diabetes. Diastolic dysfunction is also often found in ACHD patients. Similar to diastolic dysfunction in patients without congenital heart disease, it has been reported to be associated in ACHD patients with arterial hypertension, dyslipidemia, diabetes mellitus and the number of previous cardiac operations. Furthermore, it seems also to be linked to the occurrence of atrial and ventricular arrhythmias. Therefore, the consequent treatment of comorbidities like arterial hypertension could possibly lead to a reduction of diastolic dysfunction in ACHD patients and subsequently even to a reduction of the arrhythmia burden.
Some forms of congenital heart defects like tetralogy of Fallot are especially prone to ventricular arrhythmias and sudden cardiac death. This is mainly caused by inherent structural abnormalities, ventricular dysfunction and scar forming after cardiac surgery. In patients without congenital heart disease, ischaemic heart disease plays an important role in the pathogenesis of ventricular arrhythmias. Interestingly, a recent multicentre study assessing implantable cardioverter defibrillator (ICD) therapy in ACHD patients reported CAD as an independent predictor of appropriate ICD shocks. Therefore, ischaemic heart disease should also be considered as one possible cause of ventricular arrhythmias in ACHD patients and may represent an important target for risk stratification and treatment.
Chronic heart failure is an important cause for morbidity and mortality in ACHD. Its prevalence is highest in patients with complex anatomy, for example, single ventricle physiology or transposition of the great arteries. It is mainly caused by the pathophysiology of the congenital heart defect, for example, a systemic RV in congenitally corrected transposition of the great arteries, and accompanying factors like prolonged cyanosis and previous cardiac surgeries. Heart failure in ACHD is less likely to be caused by left ventricular systolic dysfunction as in the general population but is more often a consequence of right ventricular dysfunction, valve dysfunction or shunting. Diastolic dysfunction is also found in ACHD patients and often leads to heart failure. Nonetheless, considering that risk factors for the development of heart failure in the general population like arterial hypertension, diabetes and CAD to name a few are also present in ACHD patients, it seems reasonable to assume that these risk factors could also play a role in the development of heart failure in this patient group. And indeed, Giannakoulas et al reported that the association between CAD and systemic ventricular size and functional impairment in their patients suggested that CAD may contribute to ventricular dilatation and functional limitation. This is of importance since there are established treatment options for CVRF like arterial hypertension and diabetes mellitus, and also for CAD. In contrast, there is no good evidence-based treatment for heart failure in ACHD since the studies conducted so far were small, often not blinded and showed contradicting results. The few randomised controlled trials did not fulfil the expectations. Even so treatments that are established in heart failure of non-congenital origin are still used in ACHD patients despite lacking evidence.
Other Acquired Heart Conditions
Arrhythmias
Arrhythmias are a major cause of morbidity, hospitalisations and mortality in ACHD patients. Bradyarrhythmias caused by sinus node dysfunction or atrioventricular conduction abnormalities are frequently encountered as well as atrial or ventricular tachyarrhythmias. The causative factors are multifactorial and include scar tissue due to previous cardiac surgeries, inherent structural abnormalities and acquired comorbidities. Accordingly, arrhythmias are often precipitated by haemodynamic deterioration and systolic dysfunction. It has recently been recognised that diastolic dysfunction in patients without congenital heart disease is associated with atrial arrhythmias, especially atrial fibrillation. Risk factors for diastolic dysfunction include age, arterial hypertension, obesity and diabetes. Diastolic dysfunction is also often found in ACHD patients. Similar to diastolic dysfunction in patients without congenital heart disease, it has been reported to be associated in ACHD patients with arterial hypertension, dyslipidemia, diabetes mellitus and the number of previous cardiac operations. Furthermore, it seems also to be linked to the occurrence of atrial and ventricular arrhythmias. Therefore, the consequent treatment of comorbidities like arterial hypertension could possibly lead to a reduction of diastolic dysfunction in ACHD patients and subsequently even to a reduction of the arrhythmia burden.
Some forms of congenital heart defects like tetralogy of Fallot are especially prone to ventricular arrhythmias and sudden cardiac death. This is mainly caused by inherent structural abnormalities, ventricular dysfunction and scar forming after cardiac surgery. In patients without congenital heart disease, ischaemic heart disease plays an important role in the pathogenesis of ventricular arrhythmias. Interestingly, a recent multicentre study assessing implantable cardioverter defibrillator (ICD) therapy in ACHD patients reported CAD as an independent predictor of appropriate ICD shocks. Therefore, ischaemic heart disease should also be considered as one possible cause of ventricular arrhythmias in ACHD patients and may represent an important target for risk stratification and treatment.
Heart Failure
Chronic heart failure is an important cause for morbidity and mortality in ACHD. Its prevalence is highest in patients with complex anatomy, for example, single ventricle physiology or transposition of the great arteries. It is mainly caused by the pathophysiology of the congenital heart defect, for example, a systemic RV in congenitally corrected transposition of the great arteries, and accompanying factors like prolonged cyanosis and previous cardiac surgeries. Heart failure in ACHD is less likely to be caused by left ventricular systolic dysfunction as in the general population but is more often a consequence of right ventricular dysfunction, valve dysfunction or shunting. Diastolic dysfunction is also found in ACHD patients and often leads to heart failure. Nonetheless, considering that risk factors for the development of heart failure in the general population like arterial hypertension, diabetes and CAD to name a few are also present in ACHD patients, it seems reasonable to assume that these risk factors could also play a role in the development of heart failure in this patient group. And indeed, Giannakoulas et al reported that the association between CAD and systemic ventricular size and functional impairment in their patients suggested that CAD may contribute to ventricular dilatation and functional limitation. This is of importance since there are established treatment options for CVRF like arterial hypertension and diabetes mellitus, and also for CAD. In contrast, there is no good evidence-based treatment for heart failure in ACHD since the studies conducted so far were small, often not blinded and showed contradicting results. The few randomised controlled trials did not fulfil the expectations. Even so treatments that are established in heart failure of non-congenital origin are still used in ACHD patients despite lacking evidence.
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