Symptoms of myocardial infarction

Symptoms of myocardial infarction are based on three main signs:

• characteristic severe pain that lasts more than 20-30 minutes and does not subside after taking nitroglycerin;
• specific electrocardiographic data;
• laboratory parameters.

Myocardial infarction, the symptoms of which have an atypical course, can lead to diagnostic errors.

The following main clinical variants of the course of myocardial infarction are distinguished:

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ], [ 8 ]

Painful variant (status anginosus)

Pain is one of the main symptoms of developing myocardial infarction. The painful variant is observed in 70-95% of patients in the acute period of myocardial infarction. The severity of the pain syndrome can vary from unbearable pain to relatively minor pain. But in any case, the pain syndrome during myocardial infarction exceeds in strength and duration the usual pain for a particular patient, accompanying an attack of angina. The pain is usually pressing, constricting, burning, cutting. Sublingual administration of nitroglycerin and other antianginal drugs is ineffective. Even the introduction of narcotic analgesics often gives an incomplete and short-term effect.

Most often, the pain is localized behind the sternum, in the heart area, in the epigastric region. The pain can radiate to the left arm, left shoulder, shoulder blade, neck, interscapular space. The literature describes symptoms of myocardial infarction with irradiation of pain to the right arm, shoulder, both arms, lower jaw, legs.

The pain lasts from 10-20 minutes to 1-2 days. It may stop for several hours and then resume.

Patients are most often restless, groaning, unable to remain in one position. Pain syndrome in patients with myocardial infarction may be accompanied by a feeling of fear, fear of death. Sometimes the pain becomes unbearable and refractory to drug therapy from the very beginning. Such cases are most often complicated by cardiogenic shock.

There is a certain correlation between the severity of the angina status, the size of myocardial necrosis and its localization. Large focal extensive infarctions are usually accompanied by intense pain syndrome. The pain attack during a small focal infarction is usually less pronounced.

The syndrome of intense anginal pains basically corresponds to the classical description of anginal status. It is caused by acute myocardial ischemia. With the occurrence of necrosis, as a rule, the symptoms of myocardial infarction and pain cease, and in the clinical picture of the disease, the signs of resorption-necrotic syndrome come to the forefront.

Residual pains are of a dull, aching nature and do not cause any disturbances in the well-being or condition of patients.

Pericardial pain is usually stabbing, felt during deep inhalation and when changing body position, and is associated with the involvement of the pericardium in the inflammatory process.

With atypical pain syndrome, pain is felt only in the places of irradiation - pain only in the right or left arm, lower jaw, etc.

During physical examination of patients with uncomplicated myocardial infarction in the first hours after the development of pain syndrome, pallor, cyanosis of the lips, and increased moisture of the skin are detected. As a rule, pain syndrome is accompanied by the development of tachycardia (up to 100-120 beats/min), less often bradycardia. Subsequently, the heart rate in most cases returns to the values usual for a given patient (in the first hours or days). Even for uncomplicated myocardial infarction, the presence of various arrhythmias is characteristic (most often extrasystoles). Many heart rhythm disturbances occur without subjective sensations. They can arise and end unnoticed by the patient. They can be considered not as a complication of myocardial infarction, but as characteristic symptoms of myocardial infarction.

Blood pressure in the first hours of the disease at the height of the pain syndrome is often elevated. Later, it returns to the patient's usual level, or, more often, decreases slightly (mainly due to systolic). If the pain syndrome is not relieved, cardiogenic shock may develop.

The size of the heart in uncomplicated cases usually does not change. Enlargement of the heart is usually observed in complications such as ruptures of the interventricular septum and papillary muscle, cardiac aneurysms, dilatation of the left ventricle. Enlargement of the heart can also be caused by arterial hypertension, atherosclerotic and post-infarction cardiosclerosis, etc.

When palpating the heart area in patients with both transmural and non-transmural myocardial infarction, atrial pulsation, an increase in the apical impulse zone, and paradoxical pulsation to the left of the sternum are often detected.

During auscultation, already in the first hours from the development of myocardial infarction, a weakening of the first tone is noted, due to which the second tone is heard as loud. In case of an extensive infarction, muffled tones are heard. The appearance of systolic noise above the apex is possible, which is usually considered a bad prognostic sign.

A quiet systolic murmur over the apex that occurs on the second and subsequent days is regarded as a sign of relative bicuspid valve insufficiency with left ventricular dilation or damage to the papillary muscles of the left ventricle. A gallop rhythm is heard in approximately 25% of patients. Atrial gallop (IV sound) is more common than ventricular gallop (III sound). Sometimes the III and IV additional sounds merge (summation gallop). Ventricular gallop is more often observed with left ventricular insufficiency with or without cardiac dilation. Atrial gallop can be heard without heart failure. Gallop rhythm most often appears on the first or second day and stops with improvement in cardiac activity. With a sufficiently extensive infarction of the anterior wall of the left ventricle, a short-term pericardial murmur can be heard in a limited area.

Large-focal myocardial infarction is characterized by a rise in temperature to 38 °C in the first days after the development of myocardial infarction. This rise in temperature is due to the development of resorption-necrotic syndrome.

Aseptic myocardial necrosis is also accompanied by changes in the morphological picture of the blood (leukocytosis) and accelerated erythrocyte sedimentation. The temperature reaction lasts for several days and stops within a week. An increase in temperature can be caused not only by necrotic changes in the heart muscle, but also by pericarditis, parietal endocarditis and complications from other organs and systems. Myocardial infarction, especially small focal, can occur against the background of normal temperature.

Arrhythmic variant and symptoms of myocardial infarction

Heart rhythm disturbances are present to varying degrees in almost all patients with myocardial infarction. Their presence is not a basis for diagnosing arrhythmic myocardial infarction. The arrhythmic myocardial infarction is characterized by the prevalence of heart rhythm disturbances and accompanying symptoms.

The development of rhythm disturbances during myocardial infarction is based on the electrical instability of the heart, which develops as a result of disruption of the metabolic processes of the heart muscle, microcirculation and shifts in the water-electrolyte balance.

As a rule, the arrhythmic variant occurs in the form of paroxysms of gastric or supraventricular tachycardia, periods of ventricular fibrillation, atrial tachyarrhythmia, transverse block or high-grade atrioventricular block with bradysystole. Pain may not be expressed or disappear after the cardiac arrhythmia is stopped.

With this variant, arrhythmogenic cardiogenic shock often develops, and mortality is high.

The arrhythmic variant can lead to a significant deterioration in blood supply and cerebral ischemia. Often, such symptoms are regarded as a cerebral variant of myocardial infarction (for example, in the Morgagni-Adams-Stokes syndrome). But in this case, cerebral symptoms should be regarded as symptoms of myocardial infarction of the arrhythmic variant.

Despite the fact that in the arrhythmic variant, rhythm disturbances initially come to the fore, the general patterns of development and course of myocardial infarction are subsequently repeated.

[ 9 ], [ 10 ], [ 11 ], [ 12 ], [ 13 ], [ 14 ], [ 15 ], [ 16 ], [ 17 ]

Asthmatic variant

The asthmatic variant (status asthmaticus) manifests itself as an attack of suffocation as a result of the development of acute left ventricular failure. The patient complains of shortness of breath, a feeling of lack of air (a picture of cardiac asthma). The pain syndrome in this case fades into the background or is absent altogether. The absence of pain may be due to the occurrence of foci of necrosis in the zone poor in the receptor apparatus.

This variant often develops with repeated myocardial infarctions, chronic left ventricular aneurysm, and papillary muscle infarction. The asthmatic variant of myocardial infarction is characterized by significant severity and high mortality.

[ 18 ], [ 19 ]

Gastralgic variant and symptoms of myocardial infarction (status abdominalis)

This variant of myocardial infarction "simulates" the clinical picture of acute abdomen or acute gastritis. It is characterized by a combination of pain in the upper abdomen with various types of dyspeptic disorders. Patients may experience abdominal wall tension, bloating, nausea, vomiting, hiccups, acute gastric atony, intestinal paresis. The disease process may begin with vomiting, pain in the pit of the stomach, and sometimes diarrhea.

An objective examination reveals a high position of the diaphragm, an increase in the Traube space, pronounced tympanitis in the stomach area, lack of peristalsis, and a splashing sound in the stomach. In some cases, gastric atony is complicated by the development of acute gastric ulcers and the occurrence of gastrointestinal bleeding.

The development of pain in the upper abdomen is most likely due to the spread of pain impulses to the adjacent parts of the posterior horns of the spinal cord. Most often, this clinical variant is observed with lower myocardial infarctions. Sometimes similar clinical symptoms are caused by a combination of myocardial infarction and acute pancreatitis.

Cerebrovascular variant

It is relatively rare, more often in elderly patients with pronounced generalized atherosclerosis. The clinical picture is dominated by symptoms of transient cerebrovascular accident. Most often, the cerebrovascular variant of myocardial infarction manifests itself with fainting, nausea, vomiting, focal neurological symptoms. Heart pain in such patients is usually weakly expressed or absent altogether. Cerebral circulatory disorders are associated with a decrease in cardiac output, which entails hypoxia and edema of brain tissue.

In case of thrombosis and embolism of the cerebral vessels, a picture of acute cerebrovascular accident develops, which does not present any particular diagnostic difficulties.

[ 20 ], [ 21 ], [ 22 ], [ 23 ], [ 24 ], [ 25 ], [ 26 ], [ 27 ], [ 28 ], [ 29 ]

Asymptomatic variant

Sometimes myocardial infarction may be asymptomatic or with minimal manifestations of damage to the heart muscle. The patient does not pay attention to mild shortness of breath, slight pain in the heart area or their increased frequency. Perhaps such a course is due to reduced sensitivity of the nervous system, a number of constitutional factors, features of coronary circulation and metabolism disorders in the heart muscle. Asymptomatic myocardial infarction should be distinguished from painless, since, although pain is absent in both forms, other symptoms (heart rhythm disorders, blood circulation, etc.) are also absent in asymptomatic.

The incidence of silent forms of myocardial infarction ranges from 4 to 25% of all cases of myocardial infarction.

These forms of myocardial infarction are most often diagnosed by chance when a patient seeks medical attention for another disease.

Most authors regard the painful variant as a typical course of myocardial infarction. Other forms (asthmatic, arrhythmic, cerebrovascular and abdominal variants) are classified as atypical myocardial infarction. Atypical variants (except for asymptomatic) cannot be classified as uncomplicated forms of myocardial infarction.

[ 30 ], [ 31 ], [ 32 ], [ 33 ], [ 34 ], [ 35 ]