Congenital Long QT Syndrome: A Focus on Risk Stratification and Management

Figures

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  Fig. 1.. T-wave morphology specific to LQTs genotype. LQT 1 shows broad-based T-waves; LQT 2 demonstrates low-amplitude and bifid T-waves; and LQT 3 presents with a prolonged ST-segment and a late-peaking T-wave. CALM mutations, manifest earlier in life, and are associated with bradycardia and atrioventricular block, while TRDN mutation shows deeply inverted T-waves in precordial leads. LQTs, long QT syndrome; TRDN, triadin.

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  Fig. 2.. Re-classification of pathogenic variants in LQTs.

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  Fig. 3.. Assessment of patients presenting with prolonged QT interval. *Red flag symptoms include the history of syncope or a family history of unexplained sudden death. If QTc interval <500 msec with no other risk factors, reasonable to continue on medications with close monitoring of QTc interval. Fig. 3 was drawn using BioRender.

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  Fig. 4.. Management of a patient with a diagnosis of LQTs. Risk stratification is based on QTc interval and genotype, categorizing patients into low, moderate, or high-risk. Management includes avoidance of QT-prolonging drugs, and pharmalogical management with β-blockers and mexiletine. In high-risk patients, further interventions such as ICD implantation or LSCD for breakthrough arrhythmic events may be required. Ongoing risk re-assessment is critical as the clinical status and risk profile of patients may evolve. ICD, implantable cardioverter-defibrillator; LCSD, Left Cardiac Sympathetic Denervation. Fig. 4 was drawn using BioRender.