in pictures and a few words
What it is and why it matters
Ischemia is when the heart muscle doesn’t get enough blood. Sometimes it happens without chest pain, which is why it’s called “silent”.
- The good news: a check-up finds it years before a heart attack
- It’s more common in women, in diabetes, after a heart attack and in older people
- No pain doesn’t mean safe: people don’t see a doctor in time
Why the pain doesn’t get through
Pain is a signal that travels from the heart along nerves to the brain. If the path is damaged, the signal gets lost.
- With long-standing diabetes and kidney disease, thin nerves are damaged
- After a heart attack, the scar on the heart doesn’t pass on pain
- Older people feel pain more weakly; women more often have other signs
Signs the heart gives
Instead of pain, there are other signs. One at a time they mean little, but several at once in a person from a risk group are a reason to get checked.
- Shortness of breath on familiar stairs; a cold sweat with light effort
- Tiredness unrelated to sleep; jaw or back between the shoulder blades aches when walking
- Heaviness in the chest at night — easy to mistake for panic or heartburn
Important. Chest pain or pressure, shortness of breath or a cold sweat right now — call an ambulance immediately, don’t wait.
Who should get the heart checked
In these groups ischemia often comes without pain. A regular ECG at the yearly check-up is not enough for them.
- Women over 50 and people over 75
- Diabetes for more than 5 years — especially if blood sugar stays high
- A past heart attack or chronic kidney disease
How silent ischemia is found
An ordinary resting ECG often misses it: the episodes are short and may pass by the time of the recording.
- Recording the heart for 1–3 days in everyday life catches short episodes
- A scan of calcium in the heart’s vessels — once at 40–50 if there are risk factors
- Stress test with ultrasound — no radiation; in women more accurate than a treadmill test
Numbers that protect your vessels
If ischemia is caught early, it can be slowed down. For this, blood pressure, cholesterol and sugar are kept in the normal range.
- Blood pressure at high risk — below 130/80; measure at home morning and evening
- “Bad” cholesterol at high risk — below 1.8 mmol/L (70 mg/dL)
- After a heart attack or with diabetes and organ damage — below 1.4 mmol/L (55 mg/dL)
Movement, sleep and no smoking
Everyday life helps the vessels: movement, sleep, calm. Waist — under 94 cm in men and under 80 cm in women.
- Walking, swimming or cycling — 30+ minutes a day; strength training 2–3 times a week
- Sleep 7–9 hours; breathing practices against stress
- Quitting smoking: the benefit for the heart is seen after a year
Important. Supplements for the vessels — omega-3, magnesium and others — start only as planned with a doctor.
Aspirin is not for everyone
Aspirin “for prevention” isn’t needed by everyone over 50: in people without heart disease, bleeding outweighs the benefit.
- A doctor prescribes aspirin — e.g. after a heart attack or with proven heart disease
- Cholesterol medicines are also chosen by risk assessment, not by age
- Heart-pain pills started without a check-up only hide the problem
Who should see a doctor first
Have your heart checked by a doctor, even if nothing hurts, if at least one of these applies.
- A relative had a heart attack or sudden death before 60; diabetes for over 5 years
- Blood pressure above 140/90 on treatment, kidney disease, prediabetes, belly fat
- Shortness of breath, tiredness, chest heaviness at night appeared within 3–6 months
Important. Chest pain or pressure, shortness of breath or a cold sweat right now — call an ambulance immediately, don’t wait.
In one sentence
No pain doesn’t mean no ischemia. In risk groups the heart is checked in advance, and chest pain or pressure right now is a reason to call an ambulance immediately.
Introduction: Silence Is Not Safety
“I have no pain” is the most dangerous phrase in cardiology. Up to one third of all myocardial ischemia episodes occur without classic anginal pain: no pressing retrosternal burning, no radiation to the left arm, no characteristic discomfort. This is painless, or silent myocardial ischemia (SMI).
Silence does not mean lower risk. The prognosis in silent ischemia is often worse than in typical angina because the patient does not seek help, and the clinician sees no changes on a standard resting ECG. The diagnosis is made retrospectively: after myocardial infarction, after sudden cardiac death, or after the first coronary angiography showing “newly diagnosed” three-vessel disease.
This article explains why a standard ECG systematically misses painless ischemia, who is at highest risk, and which early diagnostic protocol actually works.
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Epidemiology: The Scale of a Hidden Problem
Painless ischemia is not rare and not anecdotal; it is the dominant clinical form of coronary artery disease in certain patient groups. In women, people with diabetes, older adults, and post-infarction patients, classic angina is the exception rather than the rule.
At the same time, the risk of myocardial infarction and cardiovascular death in patients with silent ischemia is comparable to, or even higher than, that in patients with typical painful ischemia.
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Mechanism: Why Pain “Does Not Arrive”
Chest pain during ischemia is a signal that passes through a chain: ischemic cardiomyocyte → afferent sympathetic fibers → dorsal horns of the spinal cord at T1–T5 → thalamus → cortex. Any disruption in this chain masks the symptom.
▸Vegetative (autonomic) neuropathy is the main mechanism in people with diabetes and patients with CKD. Hyperglycemia damages small myelinated fibers; the nociceptive signal is lost on its way to the CNS. ▸Altered myocardial innervation after infarction: scar tissue and denervated segments do not transmit pain signals. ▸High pain threshold in older adults: reduced nociceptor density and altered central signal processing. ▸Sex differences in cortical pain processing: women more often present atypically, with dyspnea, fatigue, jaw discomfort, or epigastric discomfort instead of classic retrosternal pain. ▸Short ischemic episodes: shorter than 5 minutes, insufficient to trigger a pain response but already capable of causing electrical instability.
In other words: ischemia is present, metabolic injury is occurring, the ST segment is already depressed on Holter monitoring, but the cortex does not receive the “pain” signal. The heart signals differently: through dyspnea, fatigue, nocturnal heaviness, and declining exercise tolerance.
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6 Atypical Signals: What to Look For
If classic angina is “retrosternal pressure with exertion that resolves at rest,” the atypical signals of silent ischemia look different:
▸Sudden dyspnea during usual exertion is the most common atypical equivalent. Climbing the same stairs as a month ago now causes shortness of breath. ▸Chronic fatigue unrelated to sleep: ischemic myocardium reduces cardiac output, and skeletal muscles receive less oxygen. ▸Nocturnal awakenings with chest heaviness: nocturnal decubitus angina, often misclassified as “panic attacks” or GERD. ▸Unexplained cold sweating with minimal exertion: sympathetic activation in response to ischemia. ▸Discomfort in the jaw, interscapular back, or epigastrium during movement: radiation through alternative pathways. ▸Decline in exercise tolerance over weeks or months: nonspecific, but often the only signal in older adults.
None of these symptoms is diagnostic on its own. But a combination of several atypical signals in a patient from a risk group is an indication for instrumental assessment, not for prescribing antidepressants or antacids.
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5 Risk Groups: Who Misses Classic Angina
The atypical presentation of painless ischemia does not occur in everyone, but in certain groups it becomes the dominant form.
•Women 50+: atypical presentation by default. Microvascular disease, coronary artery spasm, and INOCA (ischemia with non-obstructive coronary arteries) all produce less “classic” pain. Hospitalization occurs, on average, 6 hours later than in men. •Diabetes for 5+ years: autonomic neuropathy. The longer the duration of diabetes and the poorer the compensation, the higher the risk of missing ischemia. In patients with HbA1c >8% for more than 5 years, every second ischemic episode is painless. •Post-infarction patients: altered myocardial innervation after necrosis. The paradox is that after a first infarction, the risk of recurrent events increases while the ability to feel ischemia decreases. •Chronic kidney disease (CKD): coronary artery calcification progresses without symptoms but is visually detectable on CT. •Older adults 75+: altered pain threshold and masking of symptoms by chronic comorbidities.
If you belong to at least one of these groups, a standard resting ECG at an annual check-up is not sufficient. Targeted instrumental assessment is needed.
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Markers and Diagnostics: What Actually Shows Ischemia
A standard resting ECG is a low-sensitivity tool for detecting painless ischemia. Episodes are short, transient, and may be absent at the time of recording. What actually works:
▸CAC-score (coronary artery calcium): non-contrast computed tomography of the coronary arteries with calcification assessment. Normal is 0, risk zone >100, high risk >400. CAC >0 in a patient younger than 50 years is an indication for expanded evaluation. ▸Stress echocardiography: exercise or pharmacologic stress testing with ultrasound assessment of regional contractility. Sensitivity is ~80%, specificity ~85%. No radiation exposure and more accessible than CT coronary angiography. ▸Cardiac MRI (CMR) with pharmacologic stress: the gold standard for perfusion assessment. Especially useful in INOCA and microvascular disease. ▸Holter ECG for 24–72 hours: monitoring during usual daily life, detecting painless episodes of ST depression. ST depression ≥1 mm lasting ≥1 minute is considered ischemic. ▸Biochemical markers: lipids (including one-time Lp(a), sdLDL, apoB), hsCRP (target <1 mg/L), HbA1c (target <5.7%), NT-proBNP (increases with myocardial overload), homocysteine. ▸Exercise ECG (treadmill test): ST depression ≥1 mm during exertion. Sensitivity is lower in women and in single-vessel disease. ▸CT coronary angiography (CCTA) with assessment of stenosis and plaque characteristics (lipid-rich, fibrous, calcified, low-attenuation).
| CAC-score | Risk |
|---|---|
| 0 | normal |
| >100 | risk zone |
| >400 | high risk |
Target strategy: once per year in the presence of 2+ risk factors: reassessment with CAC-score or stress echocardiography. In patients with CAC >100: annual treatment review. In patients with diabetes for 5+ years: Holter monitoring once every 1–2 years.
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Holistic Protocol: Early Diagnosis and Risk Reduction
The goal is to detect ischemia at a stage when functional reversibility is still possible. The principle of the md_pereligyn protocol is screening by risk group, not by symptoms. Waiting for pain means missing the intervention window.
1. Screening by Risk Group
▸CAC-score: once at age 40–50 years for all men and women with risk factors (family history, diabetes, hypertension, smoking, dyslipidemia). Repeat after 5 years if CAC = 0; annually if CAC >100. ▸Holter ECG for 48–72 h: for patients with diabetes for 5+ years, post-infarction status, CKD, or CHF. ▸Stress echocardiography: when CAD is suspected in women; more sensitive than treadmill ECG. ▸Expanded biochemistry 1–2 times/year: one-time Lp(a), hsCRP, HbA1c, omega-3 index, sdLDL, apoB/apoA1.
2. Reducing Global Vascular Risk
▸Blood pressure control: target <130/80 mm Hg in high-risk patients (ACC/AHA 2017, PMID 29133356). In the SPRINT RCT (NEJM 2015, PMID 26551272), in high-risk people without diabetes, a systolic target of <120 vs <140 mm Hg lowered major cardiovascular events and all-cause mortality. Independent home monitoring in the morning and evening. ▸LDL-C: target <70 mg/dL (1.8 mmol/L) at high risk; <55 mg/dL (1.4 mmol/L) at very high risk (after infarction, diabetes with target-organ damage). ▸HbA1c: target <6.5% in younger patients with diabetes, <7% in older adults. ▸Waist circumference: <94 cm in men, <80 cm in women. Visceral fat is an independent predictor of vascular events.
3. Supporting the Endothelium and Coronary Reserve
A detailed protocol for restoring endothelial function is a separate article. Key elements:
▸Omega-3 (EPA+DHA) 2 g/day: target omega-3 index >8%. At high risk, target EPA 4 g/day (REDUCE-IT). ▸Magnesium (glycinate / taurate) 400 mg: eNOS cofactor, antiarrhythmic effect. ▸Vitamin D3 4000–6000 IU + K2 (MK-7) 100–200 μg: target 25(OH)D 60–80 ng/mL. ▸Polyphenols: pomegranate (extract) 250–500 mg, cocoa (flavanols) 500 mg, resveratrol 250 mg. Support BH4 regeneration and NO bioavailability. ▸L-citrulline 3 g/day: increases plasma arginine and improves FMD.
4. Antithrombotic Strategy: Individualized
▸Aspirin 75–100 mg: only in confirmed CAD, after acute myocardial infarction, with CAC >300, or based on individualized risk-benefit assessment. Current recommendations (USPSTF 2022) do not support aspirin for primary prevention in patients without clear risk because bleeding outweighs benefit. ▸Statins: for LDL-C >100 mg/dL and high risk, CAC >100, or familial hypercholesterolemia. Not “for everyone after 50,” but based on individualized assessment.
5. Lifestyle and Rehabilitation
▸Aerobic activity 30+ minutes/day: walking, swimming, cycling. Activates laminar shear stress and eNOS. ▸Resistance training 2–3 times/week: supports muscle mass and insulin sensitivity. ▸Sleep 7–9 hours: endothelial repair window and reduction of sympathetic tone. ▸Stress management: breathing practices, meditation, digital hygiene. Cortisol is a direct driver of endothelial dysfunction. ▸Smoking cessation: the effect on coronary risk is visible after 12 months.
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What Does NOT Work and Why
▸Standard resting ECG as the only screening tool: misses 70–80% of painless episodes. Use only in combination with Holter monitoring, CAC, and stress testing. ▸“I have no pain, so everything is fine”: in a person with diabetes for 5+ years, this statement is statistically false. Absence of pain does not mean absence of ischemia. ▸Prescribing nitrates “for discomfort” without diagnostic verification: masks symptoms and delays real diagnosis. ▸Ignoring atypical signals in women: a frequent cause of late diagnosis and worse prognosis. Women with dyspnea and fatigue receive cardiology consultation, on average, 1–2 years later than men with typical pain. ▸Prescribing antidepressants for “panic attacks” in patients from risk groups without cardiologic assessment: possible nocturnal decubitus angina is missed. ▸Preventive aspirin “for everyone after 50”: contemporary data (ASPREE, NEJM 2018, PMID 30221597) showed no cardiovascular benefit and a higher risk of major bleeding in people aged 70+ without cardiovascular disease.
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When to Seek Assessment
▸Family history of CAD, myocardial infarction, or sudden death before age 60 ▸Type 2 diabetes with duration 5+ years ▸Poorly controlled arterial hypertension (BP >140/90 on therapy) ▸Metabolic syndrome, prediabetes, visceral obesity ▸Chronic kidney disease (eGFR <60) ▸Post-infarction status, prior MI, or a previous “false alarm” cardiology presentation ▸Atypical signals: dyspnea, fatigue, nocturnal chest heaviness, decline in exercise tolerance over the past 3–6 months ▸Women 50+ with any cardiovascular risk factors
I provide comprehensive screening with CAC-score, an expanded lipid profile (sdLDL, Lp(a), apoB), Holter ECG when indicated, and a personalized risk-reduction protocol.
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Conclusion
Silent myocardial ischemia is not a rare disorder but a dominant clinical form of coronary artery disease in women, people with diabetes, post-infarction patients, and older adults. A standard resting ECG systematically misses it, and waiting for classic textbook pain is a strategy with a worse prognosis than active screening.
The principle of the md_pereligyn protocol is screening by risk group, not by symptoms. CAC-score, Holter monitoring, stress echocardiography, and expanded biochemistry are tools that detect ischemia years before myocardial infarction. At this stage, reversibility is evidence-based: correction of blood pressure, LDL-C, glycemia, omega-3 index, and endothelial function meaningfully reduces cardiovascular events.
Pain is not a prerequisite for ischemia. Silence is not safety. Detecting it earlier means treating the vessel, not its complications.
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Sources
▸Knuuti J, Wijns W, Saraste A, et al. 2019 ESC guidelines for the diagnosis and management of chronic coronary syndromes. Eur Heart J 2020;41:407–477. PMID 31504439 ▸Ridker PM, Danielson E, Fonseca FA, et al. JUPITER trial: rosuvastatin to prevent vascular events in men and women with elevated CRP. N Engl J Med 2008;359:2195–2207. PMID 18997196 ▸SPRINT Research Group. A randomized trial of intensive versus standard blood-pressure control. N Engl J Med 2015;373:2103–2116. PMID 26551272 ▸McNeil JJ, Wolfe R, Woods RL, et al. Effect of aspirin on cardiovascular events and bleeding in the healthy elderly. N Engl J Med 2018;379:1509–1518. PMID 30221597 ▸Whelton PK, et al. 2017 ACC/AHA guideline for high blood pressure in adults. Hypertension 2018;71:e13–e115. PMID 29133356
Related articles: Endothelium: The Foundation of Vascular Health, Cholesterol Without Statins.
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FAQ
If I have no chest pain, do I need cardiac screening? If you belong to at least one risk group (diabetes for 5+ years, woman 50+ with hypertension or dyslipidemia, post-infarction status, CKD, family history of CAD before age 60), then yes, absolutely. Painless ischemia is a statistically common form in these groups. CAC-score and Holter ECG can detect it years before clinical presentation.
Is a standard resting ECG sufficient to exclude CAD? No. A standard resting ECG misses up to 70–80% of painless ischemic episodes. Diagnosis requires stress tests (stress echocardiography, treadmill testing), Holter monitoring, CAC-score, and, when necessary, CT coronary angiography or CMR with perfusion.
What is CAC-score and who needs it? CAC-score (coronary artery calcium) is non-contrast computed tomography of the coronary arteries that quantifies calcification in Agatston units. Normal is 0, risk zone >100, high risk >400. It is indicated for men and women aged 40–50+ with risk factors. It is a one-time test with low radiation exposure (~1 mSv), and the result changes management in 30–40% of cases.
Can myocardial function be restored if silent ischemia is detected? Yes, partially, if it is detected before infarction. Correction of blood pressure, LDL-C, glycemia, omega-3 index, restoration of endothelial function, and lifestyle optimization slow atherosclerosis progression. Rehabilitation after ischemic episodes improves FMD and coronary reserve.
Should I take aspirin “for prevention” if I have risk factors? No, not “for everyone after 50.” Current recommendations (USPSTF 2022, ASPREE) do not support aspirin for primary prevention in patients without confirmed CAD because bleeding risk exceeds benefit. Aspirin is prescribed individually: in confirmed CAD, after acute myocardial infarction, with CAC >300, and after assessing bleeding risk.
This article is for informational purposes and does not replace medical consultation. Before starting any nutraceuticals, changing medication therapy, or undergoing diagnostic procedures, discuss the plan with your treating physician.
Key facts
- Up to one third of myocardial ischemia episodes occur without classic anginal pain.
- A standard resting ECG misses 70–80% of painless ischemic episodes.
- In patients with HbA1c >8% for 5+ years, every second ischemic episode is painless.
- ST depression ≥1 mm lasting ≥1 minute is considered ischemic.
- In women, hospitalization occurs on average 6 hours later than in men.
