Third and Fourth Heart Sounds and Myocardial Fibrosis in Hypertrophic Cardiomyopathy

Abstract

Methods Study PopulationThe present retrospective study was performed on 53 consecutive patients with HCM (mean age 66 years; range 37-91 years) who underwent an initial assessment, including phonocardiography, echocardiography, LGE-MRI, and biomarker measurements, in Matsushita Memorial Hospital. All patients were clinically stable without symptoms of heart failure, such as dyspnea, fatigue, and edema. Although these initial examinations were not necessarily performed on the same day, there were no patients with clinical conditions that changed over the period of the assessments. The diagnosis of HCM was based on the conventional echocardiographic demonstration of LV end-diastolic thickness ≥15 mm and LV end-diastolic diameter (LVEDD) ≤55 mm in the absence of any cardiac or systemic disorder that may cause LV hypertrophy, such as severe hypertension, defined as blood pressure ≥160/100 mmHg, or aortic stenosis, defined as an aortic valve area <1.5 cm 2 . Exclusion criteria were non-sinus rhythm, a previous history of myocardial T he 4th heart sound (S4) is commonly heard in patients with hypertrophic cardiomyopathy (HCM) with a sinus rhythm. 1,2 The derivation of S4 may be the result of a forceful left atrial contraction into a noncompliant left ventricle (LV). 3,4 The third heart sound (S3) is also heard, although less frequently than S4, in patients with HCM regardless of the presence or absence of heart failure. 1,2 The exact mechanism responsible for S3 in HCM patients remains unclear, reduced LV compliance due to myocardial hypertrophy has been proposed. 5 Patients with HCM often develop LV myocardial fibrosis, which may be assessed non-invasively using late gadolinium enhancement (LGE) magnetic resonance imaging (MRI). 6,7 In addition to myocardial hypertrophy, myocardial fibrosis can alter LV compliance, which leads to the development of S4 and S3; however, limited information is available on the effects of myocardial fibrosis on these extra heart sounds in patients with HCM. Thus, the aims of the present study were to examine the relationships between myocardial fibrosis, as assessed by LGE-MRI, and S3 and S4 in patients with HCM.

Absent fourth heart sound as a marker of adverse events in hypertrophic cardiomyopathy with sinus rhythm

“…A phonocardiogram was obtained at the apex as well as at the right and left sternal borders in the half left lateral decubitus position or supine position at a paper speed of 50 or 100 mm/s using a commercially available device (MES‐1000, Fukuda‐Denshi Co., Tokyo, Japan) (Honda et al, 2016 ; Sato et al, 2018 ), as shown in Figure 1 . Measurements included four frequencies: a low frequency, lower‐middle frequency, higher‐middle frequency, and high frequency.…”

“…S4 was considered to be present when a low frequency sound was recorded best at the apex between the onsets of the P wave and QRS complex of an electrocardiogram, coinciding with a large peaked A wave in an apexcardiogram if available (Tavel, 1971 ). S4 needed an amplitude of 1.0 mm or greater on the phonocardiogram with the above‐described settings (Sato et al, 2018 ). The presence or absence of S4 was assessed by two experienced cardiologists; disagreement was resolved by consensus.…”

“…Left ventricular outflow tract obstruction was considered to be present when the peak flow velocity was >2.5 m/s by the Doppler method under resting conditions or the Valsalva maneuver. Maximum left ventricular wall thickness was assessed not only on echocardiography, but also on cardiac magnetic resonance, if available, as previously prescribed (Sato et al, 2018 ).…”

“…Patients with hypertrophic cardiomyopathy (HCM) in sinus rhythm commonly show the fourth heart sound (S4) (Kawai et al, 1983 ; Sato et al, 2018 ). Since the cause of S4 is thought to be due to a forceful left atrial contraction into a non‐compliant left ventricle (Goodwin, 1982 ; Shaver et al, 1985 ), S4 may no longer be present not only in patients with atrial fibrillation (AF), but also in sinus rhythm patients with impaired atrial function (Abe et al, 1988 ; Vancheri & Gibson, 1989 ).…”

Phonocardiography: new opportunities in the light of digital technologies

“…Определение III тона для выявления очагов накопления контрастного препарата характеризо-валось высокой специфичностью (97%), но низкой чув-ствительностью (29%) [24].…”