Analysis of The Left Atrial Function Using Two-Dimensional Strain in Patients with Recent Diagnosis of Hereditary Hemochromatosis.

Hereditary Hemochromatosis (HH) is a genetic condition associated with a systemic iron overload. Heart failure is an important cause of mortality. It has been demonstrated early stages of systolic and diastolic left ventricular dysfunction in previous studies. The aim of the study is to compare the left atrial (LA) function between asymptomatic HH patients and a control group using 2D speckle tracking. Prospective study. LA strain, LA strain rate and LA volumetric parameters during the reservoir, conduit and contraction phases were studied. The LA Stiffness Index was calculated by the ratio between E/e and LA reservoir strain. 30 patients with HH (90% males, 47 ± 18 years old) and 30 healthy controls (85% males, 45 ± 13 years old) were included. LA volume was similar in both groups. No differences were observed in LA ejection fraction (EF), LA passive EF and LA active ejection fraction between both groups. On the contrary, the HH group had lower LA strain during the reservoir (31.5 ± 6.5% vs 38.3 ± 7.9%; P=0.002), and conduit phases (-18 ± 7% vs -23.3 ± 6.4%; P=0.01) and lower LA conduit strain rate (-1.7 ± 0.7 seg-1 vs -2.1 ± 0.5 seg-1; P=0.02) than controls. The LA stiffness index was significantly higher in the HH group (0.25 ± 0.9 vs 0.19 ± 0.6; P=0.01) Early abnormalities in the LA function could be detected by using 2D speckle tracking study despite no evidence of changes in atrial size or volumetric parameters.

Ecografía Doppler strain 2D en la evaluación de la función ventricular en pacientes con diagnóstico reciente de hemocromatosis hereditaria / Two-dimensional Strain Echocardiography in the Evaluation of Ventricular Function in Patients with Newly Diagnosed Hereditary Hemochromatosis

RESUMEN Introducción: La hemocromatosis hereditaria es una enfermedad genética que genera una sobrecarga sistémica de hierro, y en etapas avanzadas, puede afectar el corazón. El compromiso miocárdico precoz por esta enfermedad no ha sido suficientemente investigado. Objetivo: Comparar mediante ecocardiografía Doppler convencional y strain 2D un grupo de pacientes con diagnóstico reciente de hemocromatosis hereditaria vs. un grupo control. Material y métodos: Se estudiaron pacientes con diagnóstico reciente de hemocromatosis hereditaria, no tratados. Se les realizó un ecocardiograma Doppler convencional y con strain bidimensional para evaluar la deformación longitudinal, radial y circunferencial, y el giro y torsión del ventrículo izquierdo. Resultados: Participaron 23 varones con hemocromatosis hereditaria (46 ± 18 años) y 20 sujetos control (45 ± 15 años). No hubo diferencias en los espesores y tamaños ventriculares. Los pacientes con hemocromatosis hereditaria tuvieron una fracción de eyección del ventrículo izquierdo menor (59 ± 4% vs. 62 ± 4 %; p = 0,01). No hubo diferencias en cuanto a ESPAM, TAPSE u onda s´ del ventrículo izquierdo. Se observó una disminución significativa del strain en los pacientes con HH, con mayor compromiso de la deformación radial (37 ± 12 % vs. 55 ± 17 %; p = 0,01) y circunferencial (−19,5 ± 2,8 % vs. −22,5 ± 2,8 %; p = 0,001), y, en menor medida, de la longitudinal (−19 ± 1,8 % vs. −21,1 ± 2,5 %; p=0,04). También este grupo tuvo menor rotación apical, menor giro (17,7 ± 13° vs. 25 ± 7°; p = 0,03) y menor torsión (2,3 ± 1,8 °/cm vs. 3,3 ± 1,1 °/cm; p = 0,03). No hubo correlación entre los diferentes tipos de deformación y los parámetros bioquímicos del metabolismo férrico. Conclusiones: La ecocardiografía y especialmente la evaluación del strain 2D es capaz de detectar de manera temprana ligeras alteraciones de la mecánica ventricular en pacientes asintomáticos, con sobrecarga sistémica de hierro por hemocromatosis hereditaria.

ABSTRACT Background: Hereditary hemochromatosis is a genetic disorder characterized by systemic iron overload which can involve the heart in advanced stages. Early myocardial involvement has not been thoroughly investigated. Objective: The aim of our study was to evaluate the performance of conventional Doppler-echocardiography and 2D strain echocardiography in a group of patients with newly diagnosed hereditary hemochromatosis vs. a control group. Methods: Patients with newly diagnosed hereditary hemochromatosis without treatment were included. All the patients underwent conventional Doppler echocardiography and 2D strain echocardiography with evaluation of left ventricular longitudinal, radial and circumferential strain, twist and torsion. Results: Twenty-three male patients with hereditary hemochromatosis (46±18 years) and 20 male controls (45±15 years) were included. There were no differences in ventricular dimensions and wall thickness. Left ventricular ejection fraction was lower in patients with hereditary hemochromatosis (59±4% vs. 62±4%; p=0.01). There were no differences in MAPSE, TAPSE and left ventricular s' velocity. There was a significant decrease in global strain in patients with hereditary hemochromatosis, with greater involvement of radial strain (37±12 % vs. 55±17%; p=0.01) and circumferential strain (-19.5±2.8% vs. -22.5±2.8%; p=0.001), and less involvement of longitudinal strain (-19±1.8% vs. -21.1±2.5%; p=0.04). Myocardial rotation showed lower twist (17.7±13° vs. 25±7°; p=0.03) and lower torsion (2.3±1.8°/cm vs. 3.3±1.1 °/cm; p=0.03). There was no correlation between the different strain parameters and iron metabolism. Conclusions: Echocardiography, and particularly 2D strain analysis can detect early abnormalities of ventricular mechanics in asymptomatic patients with systemic iron overload due to hereditary hemochromatosis.