OBJECTIVES: This study characterizes left ventricular outflow tract (LVOT) gradient variability in patients with hypertrophic cardiomyopathy (HCM) during cardiac catheterization. BACKGROUND: Management of HCM is directed by the presence and magnitude of LVOT obstruction. The magnitude and clinical impact of spontaneous variability during a single cardiac catheterization has not been described. METHODS: Fifty symptomatic patients with HCM (mean age 55 ± 15 years; 48% men) underwent cardiac catheterization with high-fidelity, micromanometer-tip catheters and transseptal measurement of left ventricular pressures. Obstruction was defined as resting LVOT gradient ≥ 30 mm Hg and severe obstruction as ≥ 50 mm Hg. Variability in LVOT gradient was calculated as the difference of the largest and smallest LVOT gradients in the absence of provocative maneuvers or interventions. RESULTS: The largest LVOT gradient was 54.6 ± 56.4 mm Hg. The spontaneous variability in LVOT gradient was 49.0 ± 53.1 mm Hg (range 0 to 210.8 mm Hg, median 15 mm Hg). Discrepant classification of resting LVOT gradient severity was possible in 25 patients (50%). Twenty patients (40%) with severe obstruction could have been misclassified with regard to obstruction severity. CONCLUSIONS: In patients with HCM, the LVOT gradient fluctuates significantly during a single hemodynamic assessment. Spontaneous variability could lead to misclassification of obstruction severity in one-half of studied patients. The dynamic nature of LVOT obstruction must be considered when assessing resting hemodynamics or the success of a given intervention during cardiac catheterization.
OBJECTIVES: This study characterizes left ventricular outflow tract (LVOT) gradient variability in patients with hypertrophic cardiomyopathy (HCM) during cardiac catheterization. BACKGROUND: Management of HCM is directed by the presence and magnitude of LVOT obstruction. The magnitude and clinical impact of spontaneous variability during a single cardiac catheterization has not been described. METHODS: Fifty symptomatic patients with HCM (mean age 55 ± 15 years; 48% men) underwent cardiac catheterization with high-fidelity, micromanometer-tip catheters and transseptal measurement of left ventricular pressures. Obstruction was defined as resting LVOT gradient ≥ 30 mm Hg and severe obstruction as ≥ 50 mm Hg. Variability in LVOT gradient was calculated as the difference of the largest and smallest LVOT gradients in the absence of provocative maneuvers or interventions. RESULTS: The largest LVOT gradient was 54.6 ± 56.4 mm Hg. The spontaneous variability in LVOT gradient was 49.0 ± 53.1 mm Hg (range 0 to 210.8 mm Hg, median 15 mm Hg). Discrepant classification of resting LVOT gradient severity was possible in 25 patients (50%). Twenty patients (40%) with severe obstruction could have been misclassified with regard to obstruction severity. CONCLUSIONS: In patients with HCM, the LVOT gradient fluctuates significantly during a single hemodynamic assessment. Spontaneous variability could lead to misclassification of obstruction severity in one-half of studied patients. The dynamic nature of LVOT obstruction must be considered when assessing resting hemodynamics or the success of a given intervention during cardiac catheterization.
Authors: Bradley D Allen; Lubna Choudhury; Alex J Barker; Pim van Ooij; Jeremy D Collins; Robert O Bonow; James C Carr; Michael Markl Journal: Eur Heart J Cardiovasc Imaging Date: 2014-08-09 Impact factor: 6.875
Authors: Terry D Bauch; Alexandra J Smith; Joseph P Murgo; James A Watts; Bernard J Rubal Journal: Catheter Cardiovasc Interv Date: 2018-11-25 Impact factor: 2.692
Authors: Konstantinos C Siontis; Jeffrey B Geske; Kevin Ong; Rick A Nishimura; Steve R Ommen; Bernard J Gersh Journal: J Am Heart Assoc Date: 2014-06-25 Impact factor: 5.501