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PISA--a new noninvasive method for early detection and quantification of ischemia in hypertensive patients
Insights
Hypertension can cause cardiac damage, but early detection is possible. A new noninvasive method, Phase-Invariant Signature Algorithm (PISA), shows promise for identifying cardiac complications in hypertensive patients.
Area of Science:
- Cardiology
- Medical Diagnostics
- Hypertension Research
Background:
- Untreated hypertension leads to cardiac damage via myocardial effects or accelerated coronary atherosclerosis.
- Current diagnostic tools detect cardiac complications at advanced stages, missing opportunities for early intervention.
- Early detection of cardiac complications in hypertension is crucial for timely treatment and potential reversal.
Purpose of the Study:
- To evaluate the efficacy of the noninvasive Phase-Invariant Signature Algorithm (PISA) for detecting myocardial ischemia and/or infarction in hypertensive patients.
- To assess PISA's sensitivity and specificity in differentiating between healthy individuals, patients with known ischemic heart disease, and hypertensive patients.
- To determine if hypertensive patients without end-organ disease exhibit signs of cardiac ischemia detectable by PISA.
Main Methods:
- Employed the Phase-Invariant Signature Algorithm (PISA), a novel noninvasive diagnostic method.
- Studied three groups: 25 healthy individuals, 20 patients with documented ischemic heart disease, and 50 hypertensive patients on medication (1-6 years duration, no end-organ disease).
- Analyzed PISA signatures and PISA index values to identify phase-variant signatures and elevated PISA indices indicative of cardiac abnormalities.
Main Results:
- Healthy individuals exhibited phase-invariant PISA signatures and low PISA indices.
- All 20 patients with known ischemic heart disease showed phase-variant signatures and high PISA indices.
- PISA demonstrated 100% sensitivity in detecting ischemic heart disease.
- Twenty-nine of 50 hypertensive patients (58%) presented with phase-variant PISA signatures and elevated PISA indices, suggesting possible ischemic heart disease.
- Specific locations of ischemia/infarction were identified in these 29 patients: 8 with anterior wall, 10 with inferior wall, and 11 with both.
Conclusions:
- The PISA method is highly sensitive (100%) for detecting ischemic heart disease.
- A significant proportion of hypertensive patients without overt end-organ disease may have subclinical myocardial ischemia and/or infarction detectable by PISA.
- PISA offers a promising noninvasive tool for early diagnosis of cardiac complications in hypertensive individuals, enabling prompt therapeutic intervention.
Abstract:
Hypertension if untreated, is known to produce cardiac damage. Cardiac complications result from the effects of hypertension on the myocardium and/or to accelerated atherosclerotic changes in the coronary arteries. Presently available diagnostic tools are able to detect cardiac complications only when they are relatively at an advanced stage. Early detection of cardiac complications would have the advantage of early treatment, with potential for reversal. PISA (Phase-Invariant Signature Algorithm) - a new noninvasive method has been shown by us to have high sensitivity and specificity for diagnosis of ischemic heart disease. This method was therefore used in 25 healthy individuals, 20 patients with documented ischemic heart disease and 50 hypertensive patients (duration 1-6 years) with no end-organ disease in order to determine if these patients have myocardial ischemia and/or infarction. These patients were on antihypertensive medication. Healthy individuals as expected, had phase-invariant PISA signature and low PISA index. All 20 patients with documented ischemic heart disease had phase variant signature and had high PISA index in two or more leads. The sensitivity of this method for detection of ischemic heart disease was found to be 100%. Twenty-nine of the 50 hypertensive patients were found to have phase-variant (abnormal) PISA signatures and their PISA index was beyond the upper limit of normal PISA range (mean + 3S.D. of healthy individual). This study suggests that these 29 hypertensive patients possibly have ischemic heart disease. This PISA study indicates that 8 patients have anterior wall, 10 inferior wall, and 11 both anterior and inferior wall ischemia and/or infarction. These twenty-nine patients have varying degree of ischemia and/or infarction.