E_Stethoscope: Portable Digital Auscultation Study on Hypertensive/Hypertensive Heart Disease Patients
E_Stethoscope: Portable Digital Auscultation Study on Hypertensive/Hypertensive Heart Disease Patients
Hypertensive heart disease (HHD) is a heart condition that is caused by chronic exposure to
 high blood pressure. In patients with HHD, abnormalities in the way heart muscle relaxes and
 how heart chambers passively fill with blood (diastolic dysfunction) can occur that may be
 detected on echocardiography (echo), which is a standard clinical method to examine heart
 structure and function using reflected sound waves. Investigators propose to develop a
 digital auscultation system or electronic stethoscope based on wireless sensor node
 technique. Investigators hypothesize that the heart sounds measurements detected by
 electronic stethoscope can be used to detect heart diastolic dysfunction in HHD .
Study proposal aims to look into treatment of hypertension (HT) and its complications of the
 exact high healthcare costs. In 2004, Singapore adult prevalence of hypertension was 20.1%.
 World Health Organization estimates that HT causes 4.5% of global disease burden, and that
 62% of cerebrovascular disease and 49% of ischemic heart disease are attributable to
 suboptimal blood pressure (BP) control.

 Recently, scrutiny has been focused on appropriate BP levels at which to initiate HT
 treatment with the benefit of strict BP targets in otherwise uncomplicated HT is questioned,
 as HT drug treatment is not without risks. This underscores the need to stratify hypertension
 patients according to target organ damage, so that affected HT patients may be selected for
 intensive BP lowering.

 Hypertensive heart disease (HHD) is a heart condition that is caused by chronic exposure to
 high BP. As population ages, both HT and Hypertensive Heart Disease prevalence increase.
 Genetic and hemodynamic factors interact to cause Hypertensive Heart Disease in patients with
 hypertension. In patients with Hypertensive Heart Disease , abnormalities of both myocardial
 relaxation and passive filling may be detected sometimes on echocardiography (echo). These
 diastolic dysfunctions are due to various mechanisms but central to the pathophysiology is an
 increase in myocardial stiffness. Early symptoms of myocardial stiffness caused by left
 ventricular hypertrophy (LVH) is a good early indicator for cardiovascular target organ
 damage in patients with HT and Hypertensive Heart Disease . Hypertensive Heart Disease
 patients constitute a group in which intensive BP treatment with drugs to strict targets are
 shown to yield favourable benefit risk ratios. As such, the identification of Hypertensive
 Heart Disease patients becomes paramount.

 An electrocardiogram (ECG) monitors and records the heart's electrical activity. ECG is
 insensitive to detect diastolic dysfunction with sensitivity from 12% to 50%. An echo takes a
 picture of the heart using ultrasound. Echo can be used to diagnose diastolic function,
 however, no one single echo parameter can make the diagnosis. Multiple echo parameters have
 been proposed including mitral inflow velocity pattern, pulmonary vein flow patterns and
 tissue Doppler measurements, but imprecise. Existing ultrasound scans cost in the range of
 US$300-$600 which are reimbursable under Medicaid (the payer). A coronary angiography
 examines the flow of blood through the heart by inserting a catheter into the heart. It is
 too invasive and too costly. Therefore, there is appealing need to have a cheaper
 non-invasive solution that would be able to detect diastolic function. That will have largest
 impact on patients management and on payers.

 A cheap, non-invasive and sensitive solution that permits detection via auscultation of
 abnormal heart sounds, indicating stiff heart muscle associated with Hypertensive Heart
 Disease among HT patients is critically needed. Cardiac auscultation (listening to heart
 sounds) is possible option as heart sounds are associated with myocardial function and
 dysfunction .In a normal heart, two heart sounds (S1 and S2) are audible, corresponding to
 closure of the mitral and aortic heart valves respectively. A third heart sound S3, occurring
 after S2 is present in some heart failure. A fourth heart sound S4, occurring just before S1,
 is due to forceful contraction of the atrium to overcome a stiff or hypertrophic left
 ventricle . Human ears are not well equipped to detect such abnormities consistently with a
 conventional stethoscope. Therefore, investigators propose to develop a low power,
 non-invasive, portable device which is based on Wireless Sensor Node (WSN) technology to
 achieve our goal of portable auscultation.Proposed device will allow a monitoring/recording
 of heart sounds in-situ and perform preliminary assessment of diastolic function that is
 physiologically meaningful, reproducible and validated. Multiple devices can also be placed
 and used concurrently at different sites over the torso to enhance chances of detecting
 abnormal heart sounds.
Inclusion Criteria:

 1. Participants with clinically suspected or known HT/Hypertensive Heart Disease who have
 been scheduled for echocardiography examination and/or cardiac catheterization.

 2. Participants with history of high BP and stable medication for at least 2 weeks.

 3. Presence of the following :

 Elevated BP measurement or Left ventricular hypertrophy (LVH) on either prior ECG or prior
 echo.

 Exclusion Criteria for patient

 1. Participants with heart muscle disease.

 2. Participants with significance valve disease.

 Exclusion Criteria for volunteer:

 1. Strictly exclude hypertensive for Normal healthy volunteers.

 2. Not on any anti-hypertensive agents.