Emergencies in Cardiology

Basics of Diagnosing Syncopal States

The cornerstone of diagnosing syncope is a detailed medical history and a careful clinical examination. The physician must ascertain the exact circumstances under which the attack developed.

Key anamnesis factors:

• Body position before loss of consciousness: whether the patient was standing, sitting, or lying down.
• Nature of activity: exactly what the person was doing at the time the syncope occurred.
• Precipitating factors: stress, pain, medical procedures.
• Medication history: what drugs the patient is taking, as discontinuing or adjusting the dose is often the primary treatment method.

Electrocardiography (ECG) is mandatory for all patients with syncope. If the etiology is unclear, an in-depth examination is required to rule out life-threatening conditions that necessitate urgent prevention.

Additional diagnostic methods for unclear etiology

If basic diagnostics yield no answers, an expanded range of tests is used. Each method aims to rule out specific pathology:

1. Laboratory diagnostics: a complete blood count (CBC) helps detect anemia by a drop in hemoglobin levels, and a blood glucose test rules out hypoglycemia.
2. Holter ECG monitoring: necessary to detect paroxysmal arrhythmias that may not be captured on a standard ECG.
3. Orthostatic test: used to confirm orthostatic hypotension and peripheral autonomic failure.
4. Carotid sinus massage (sinocarotid test): allows verification of carotid sinus syncope.
5. Hyperventilation test: performed to diagnose hyperventilation attacks, which often occur as part of anxiety and phobic disorders.

At the slightest suspicion of a cardiogenic origin of syncope, a cardiology consultation and echocardiography (EchoCG) are prescribed. If there is a suspicion of a transient ischemic attack (TIA) in the vertebrobasilar system, ultrasound/duplex scanning of the vertebral and carotid arteries, as well as CT or MR angiography, are indicated.

Emergency care for neurogenic syncope

Neurogenic syncopes often develop against the background of medical procedures such as blood draws or dental interventions. Action must be swift and follow a clear algorithm.

Tactics for presyncopal states:

• Quickly lay the patient down in a horizontal position.
• Or rapidly tilt their head and torso downward if they are in a sitting position.

Actions during syncope:

• Place the patient on their back.
• Elevate the legs — this is necessary to urgently improve venous return to the heart.
• Free the neck and chest from restrictive clothing, loosen the collar.

Measures to accelerate the return of consciousness:

• Splash cold water on the patient's face.
• Apply a cold, damp towel to the forehead.
• Have them inhale ammonia vapor (sal volatile/ammonia spirits).

After the patient regains consciousness, they must remain in a horizontal position for 10–15 minutes to prevent recurrence.

Prevention and treatment based on the underlying cause

Further patient management entirely depends on the established etiology of the syncope:

• Neurogenic syncope: in most cases, simply avoiding known triggers is sufficient.
• Orthostatic syncope: the patient is advised to avoid rapidly transitioning to an upright position (do not stand up abruptly) and to ensure adequate fluid intake (2 to 3 liters per day). Simultaneously, etiopathogenetic treatment for the cause of orthostatic hypotension is carried out.
• Cardiogenic syncope: the most dangerous group. In the acute phase, it may require emergency resuscitation measures, including the use of a defibrillator or pacemaker implantation. Preventing recurrent episodes requires comprehensive diagnostics and treatment of the underlying condition by a cardiologist.
• Syncope against the background of TIA: requires strict measures for the prevention of ischemic stroke.
• Syncope of other etiologies: treatment of the underlying disease or discontinuation (dose reduction) of the drug that triggered the attack is of primary importance.

Class and exam questions

What else to study on this topic

• Criteria and methodology for performing carotid sinus massage
• Differential diagnosis of AV blocks on ECG in syncope
• Indications for pacemaker implantation in cardiogenic syncope
• Pathogenesis of transient ischemic attack in the vertebrobasilar system
• Peripheral autonomic failure: etiology and manifestations

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.