Apical Sparing of Longitudinal Strain and Myocardial Fibrosis in Hypertensive Patients and Spontaneously Hypertensive Rats: Based on Speckle Tracking and Histological Analysis

Clin Cardiol. 2026 Jan;49(1):e70255. doi: 10.1002/clc.70255.

Abstract

Background: This study aimed to investigate regional myocardial strain and fibrosis distribution to analyze the apical sparing pattern and the relation with hypertrophy in hypertension.

Methods: This study included clinical and experimental animal investigations. Seventy-three hypertensive patients were divided into two groups: hypertension without left ventricular hypertrophy (HT-NLVH) and hypertension with LVH (HT-LVH). Six 16-week-old male spontaneously hypertensive rats (SHR) and six age-matched male Wistar-Kyoto (WKY) rats were included in this experiment. Echocardiographic measurements were obtained. Myocardial strain indexes, including global longitudinal strain (GLS), the basal, middle, and apical segmental LS (LS-bas, LS-mid, LS-ap), and the proportion of LS-ap/(LS-bas + LS-mid + LS-ap) (P-ap) were measured. The histological collagen volume fraction (CVF) and perivascular collagen area (PVCA) of basal and apical segments (CVF-bas, CVF-ap, PVCA-bas, PVCA-ap) were observed in all rats.

Results: Despite preserved systolic function (FS, LVEF), the HT-NLVH and HT-LVH groups exhibited diastolic impairment (elevated LAVI, E/e') (all p < 0.05). LS-ap declined only in HT-LVH, while LS-mid and LS-bas worsened from HT-NLVH to HT-LVH, and the HT-LVH group exhibited a significantly elevated P-ap (all p < 0.05). P-ap was associated with LV remodeling indexes and E/e' (all p < 0.05). Compared with WKY, LS-bas decreased in SHR (p < 0.05). The SHR group demonstrated significantly elevated PVCA-bas, PVCA-ap, and CVF-bas (p < 0.05), while the CVF-ap had no significant difference.

Conclusion: Myocardial dysfunction and fibrosis exhibited regional heterogeneity with predominant basal damage and apical sparing in hypertensive cardiac hypertrophy. This apical-sparing pattern correlated significantly with both diastolic dysfunction and hypertrophic progression, suggesting its potential as a clinically observable hallmark.

Keywords: apical sparing; fibrosis; hypertension; longitudinal strain; systolic function.

MeSH terms

  • Animals
  • Disease Models, Animal
  • Echocardiography* / methods
  • Female
  • Fibrosis
  • Humans
  • Hypertension* / complications
  • Hypertension* / diagnosis
  • Hypertension* / physiopathology
  • Hypertrophy, Left Ventricular* / diagnosis
  • Hypertrophy, Left Ventricular* / diagnostic imaging
  • Hypertrophy, Left Ventricular* / etiology
  • Hypertrophy, Left Ventricular* / physiopathology
  • Male
  • Middle Aged
  • Myocardium* / pathology
  • Rats
  • Rats, Inbred SHR
  • Rats, Inbred WKY
  • Stroke Volume
  • Ventricular Function, Left* / physiology
  • Ventricular Remodeling