Cardiac Function Report



Cardiac Function

Analyze Heart Rhythm

The CardioSleeve stethoscope attachment records  High-Fidelity 3- Lead ECG tracings with a digital caliper to be viewed and analyzed on a connected device.

Identify Heart Failure

CardioSleeve's advanced cutting-edge technology detects heart failure at any point of care.




Cardiac Function Report



Systolic Time Intervals – Parameter Overview

Rijuven’s CardioSleeve technology captures, synchronizes and algorithmically interprets simultaneous digital Heart Sound and ECG. Rijuven provides a non-invasive and easy way to evaluate heart function to give a complete electrical and hemodynamic view of the heart. Rijuven’s technology is based on well-known Systolic Time Interval (STI) fundamentals i. Rijuven identifies and quantifies normal and abnormal heart sounds related to the left ventricle, and determines the timing of those heart sounds in every cardiac cycle in relation to the onset of the P wave and QRS complex from the simultaneously recorded ECG.

Rijuven’s STI technology produces a variety of measurements, including the duration of systolic time intervals that have been shown to correlate with established measures of cardiac function, and have proven to provide prognostic information relevant for the optimization of cardiac treatment.

CardioSleeve Systolic Time Intervals

Head to head comparison of Systolic Time Intervals
Echocardiogram and CardioSleeve

CardioSleeve Systolic Time Intervals


ICT= Isovolumic Contraction Time
IRT= Isovolumic Relaxation Time
ET (or EP) = Ejection Time (or Period)



Systolic Performance Index

For the first time, the integration of an already proven exciting, new, easy-to-use, modernized cutting edge technology of Systolic Performance Index has been added to the hallmark of the physician.

What is SPI?

The technique incorporates simultaneous acquisition and quantitative measurements of combined ECG and cardiac acoustical data. This permits acquisition of detailed information regarding systolic left ventricular function and provides both a computerized interpretation and a visual display of the findings. 

SPI is a simplified Myocardial Performance index (MPI) or (Tei index).

Mycardial performance Index (MPI) has been regarded as an important parameter in the evaluation of ventricular systolic function in congestive heart failure.  The myocardial performance index (MPI) or (Tei index), which predicts systolic and diastolic function, is defined as the sum of isovolumic relaxation time (IVRT) and isovolumic contraction time (IVCT) divided by left ventricular ejection time (LVET) (MPI=[IVRT+IVCT]/LVET).

The MPI formula was simplified by omitting IVRT (IVCT/LVET), to define Systolic Performance Index (SPI). The SPI ratio was found to be inversely correlated with left ventricular ejection fraction (LVEF) and positively correlated with MPI. The sensitivity and specificity of an SPI value ≤0.66 to predict an LVEF value ≥55% were found to be 100% and 90.9%, respectively. In terms of SPI, this ratio was found to be >0.66, even exceeding 1 in severe CHF (LVEF ≤20%).


Benefits of Systolic Performance Index

The ease of use and low cost of SPI makes it useful for the evaluation and monitoring of patients with known or suspected heart disease in a variety of clinical settings.



Heart Failure

The early identification of Heart Failure and its presence has significant prognostic and economic implications. SPI value can assist clinicians in assessing patients in the emergency department or office for detecting acute decompensated heart failure. It gives instant results as compared to BNP laboratory analysis (which may take few hours) and may also help resolve a significant amount of the indeterminate BNP values.



Misdiagnosis Correction

Patients with sufficiently subtle or complicated heart failure are often misdiagnosed as Pneumonia and COPD. SPI is helpful useful in identifying acute decompensated heart failure in subjects who had no prior history of heart failure, had a history of COPD, had a prior EF > 40% and an indeterminate BNP of <500 pg/ml.




SPI can detect changes in hemodynamic status and follow patients who are receiving cardiotoxic chemotherapeutic agents such as Doxorubicin and other anthracycline derivatives, which at present involve repetitive echocardiographic studies.



Mass Screening

The ease of use and low cost of SPI makes it highly practical for mass screening large populations of patients i.e. screening for early detection of rheumatic heart disease in areas where the disease is endemic (e.g. Africa and Southeast Asia).



Sports Screening

In developed countries, idiopathic hypertrophic subaortic stenosis remains the most common cause of non-traumatic sudden death in young people. By readily providing simultaneous ECG and heart sound data, it is useful in screening young people for this disease (e.g. prior to their participation in strenuous sports).