Ischemic heart disease: definition and causes
Coronary heart disease (CHD) is characterized by myocardial injury resulting from impaired oxygen delivery to a region of the heart muscle. The main cause is coronary artery atherosclerosis: low-density lipoproteins are deposited in the vascular intima, forming an atherosclerotic plaque. The plaque partially occludes the lumen, aerobic glycolysis is replaced by anaerobic glycolysis, and ischemia develops. When the plaque ruptures, platelets aggregate on its surface, the lumen becomes occluded, and myocardial necrosis — infarction occurs.
Less commonly, IHD is caused by coronary artery spasm, which is a functional and usually reversible condition. Atherosclerosis is a systemic disease: when coronary arteries are affected, plaques are often also found in the brachiocephalic, carotid, and limb arteries. Therefore, patients after a myocardial infarction are indicated for brachiocephalic artery ultrasound.
Acute and chronic coronary syndromes
IHD encompasses both acute and chronic forms. Acute coronary syndrome (ACS) is divided into ST-elevation ACS and non-ST-elevation ACS. Non-ST-elevation ACS includes non-ST-elevation myocardial infarction and unstable angina; they are differentiated by measuring troponin twice: a rising level indicates infarction, while a negative result indicates unstable angina.
Chronic coronary syndromes include:
- stable exertional angina;
- dyspnea as an equivalent of angina;
- myocardial ischemia due to vasospasm;
- silent myocardial ischemia.
Clinical presentation and differential criteria
Typical pain in ACS is pressing, burning, squeezing, localized retrosternally with radiation to the left arm, shoulder, neck, lower jaw, interscapular region, or epigastrium. It is accompanied by autonomic symptoms: pallor, sweating, nausea, less frequently vomiting without relief, and compensatory tachycardia.
Five criteria for the clinical presentation of ACS:
- character — pressing, burning, squeezing;
- localization — retrosternal;
- radiation — typical zones;
- intensity — high, poorly relieved;
- duration — more than 20 minutes, does not resolve at rest.
Atypical manifestations include epigastric pain, syncopal states, and arrhythmias. In cases of epigastric pain, emergency teams routinely perform an ECG to rule out ACS. In chronic forms, pain is shorter in duration, is effectively relieved by nitroglycerin, is provoked by physical exertion and stress, and subsides at rest.
Management tactics in IHD
In ACS, the goal is to limit the zone of myocardial injury. Urgent reperfusion (coronary angiography with restoration of blood flow) is performed, and dual antiplatelet therapy is prescribed: acetylsalicylic acid combined with ticagrelor or clopidogrel for a duration of one year, followed by aspirin monotherapy. In low-risk unstable angina, coronary angiography can be delayed. In chronic coronary syndromes, the objective is to improve quality of life and prevent the development of ACS through pharmacotherapy.
Arterial hypertension
Arterial hypertension is a syndrome of elevated blood pressure exceeding 140/90 mm Hg. Essential hypertension is an independent primary disease; secondary arterial hypertension develops secondary to adrenal cortex tumors, thyrotoxicosis, or renal pathology.
Stages of essential hypertension are determined by target organ damage:
- Stage I — absence of target organ damage;
- Stage II — left ventricular hypertrophy, initial renal function impairment;
- Stage III — associated clinical conditions (infarction, stroke, rhythm disorders).
Cardiovascular risk is calculated using the SCORE (40–69 years) and SCORE2-OP (over 70 years) scales; relative risk is used for patients aged 18–39 years. Diagnosis includes 24-hour ambulatory blood pressure monitoring and home blood pressure monitoring. The basis of treatment is non-pharmacological therapy: weight loss, salt restriction, quitting alcohol and smoking. Pharmacological classes include: ACE inhibitors or ARBs, calcium channel blockers, thiazide/thiazide-like diuretics, beta-blockers (only in the presence of concomitant IHD, CHF, arrhythmias, or tachycardia).
Chronic heart failure
CHF is a complex of symptoms developing as a result of impaired cardiac pumping function: dyspnea, fatigue, edema. CHF is always a complication of another disease and is recorded in the diagnosis specifically as a complication.
Classification by left ventricular ejection fraction (by echocardiography):
- reduced — less than 40%;
- moderately reduced — 41–49%;
- preserved — 50% or more.
The modern stage-based classification distinguishes a pre-stage (structural changes without symptoms), stage 1 (initial symptoms), and stage 2 (decompression / decompensation). The functional class reflects exercise tolerance. Diagnosis rests on three pillars: clinical presentation, NT-proBNP levels, and echocardiography.
Treatment of CHF
The gold standard is quadruple therapy, prescribed for life:
- SGLT2 inhibitors (dapagliflozin, empagliflozin);
- beta-blockers;
- mineralocorticoid receptor antagonists;
- renin-angiotensin-aldosterone system blockers.
Discontinuation of medications is prohibited even if the ejection fraction improves — the improvement has been achieved precisely thanks to the therapy. The drugs prevent myocardial remodeling and can contribute to the regression of fibrotic changes.
Non-pharmacological principles: patient education, self-monitoring (daily weighing to track fluid retention), salt restriction, fluid restriction in the range of 1–1.5 liters per day (less than 1 liter is harmful to the kidneys, more than 1.5 is a load on the heart), dosed physical activity, quitting bad habits, mandatory vaccination.
Key points
- The main cause of IHD is coronary artery atherosclerosis; atherosclerosis is systemic.
- Differentiation between non-ST-elevation myocardial infarction and unstable angina is based on measuring troponin twice.
- Five criteria for pain in ACS: character, localization, radiation, intensity, duration of more than 20 minutes.
- In ACS, urgent reperfusion and dual antiplatelet therapy for 12 months are indicated.
- The stage of essential hypertension is determined by target organ damage and the presence of associated clinical conditions.
- Beta-blockers are not prescribed for isolated arterial hypertension.
- CHF is always a complication; diagnosis relies on clinical presentation, NT-proBNP, and echocardiography.
- Quadruple therapy for CHF (SGLT2 inhibitors, beta-blockers, MRAs, ACEIs/ARBs/ARNI) is prescribed for life.