2.5. TAHIKARDIA

Related terms.

Supraventricular tachycardia, ventricular tachycardia, multifocal atrial tachycardia, polymorphic ventricular tachycardia, pirouette tachycardia, atrial fibrillation, atrial flutter.

Purpose of care

1. Maintain adequate oxygenation, ventilation and perfusion.

2. Control of heart rate.

3. Restoring normal sinus rhythm in unstable patients.

4. Identification of the root cause:

a) medications (caffeine, dietary supplements, thyroid drugs, cold medications);
b) narcotic substances (cocaine, amphetamine);
c) history of arrhythmia;
d) acute and congestive heart failure

Patient description

Patients may have an elevated heart rate due to age and may or may not be associated with symptoms such as palpitations, dyspnea, chest pain, syncope/presyncope, hemodynamic disturbances, altered mental status, or other signs of impaired perfusion of major organs.

Inclusion criteria

Heart rate above 100 bpm in adults and relative tachycardia in children.

Exclusion criteria

Sinus tachycardia..

Patient management

Assessment, treatment and intervention

1. Management of adult patients

1.1. Airway management (if necessary).
1.2. Conducting (if necessary) oxygen therapy to achieve saturation in the range of 94-98%.
1.3. Monitoring of vital signs and recording of ECG in 12-leaders.
1.4. IV access.
1.5. Checking blood glucose levels and treating hypoglycemia according to the guideline “Hypoglycemia”.
1.6. Remember to apply the following additional therapeutic measures if symptoms of tachycardia or hemodynamic instability persist:

1) Tachycardia with a narrow complex, regular – stable supraventricular tachycardia (SVT):

a) perform vagal tests;
b) adenosine 6 mg IV followed by 10 ml of saline bolus:

• • • • if tachycardia continues, administer another 12 mg of adenosine IV;
      • a third dose of adenosine 12 mg IV may be administered;

c) diltiazem 0.25 mg/kg IV over 2 minutes:

• • • • a second dose of diltiazem 0.35 mg/kg IV may be administered after 15 minutes if necessary;
      • for patients over 65 years of age, the recommended maximum initial dose of diltiazem is 10 mg IV and the maximum repeated dose is 20 mg;

d) metoprolol 5 mg IV for 1-2 minutes, the procedure can be repeated if necessary every 5 minutes, the maximum number of doses is 3.

2) Tachycardia with a narrow complex, regular – unstable:

a) perform a synchronized electrical cardioversion (follow the recommendations of the defibrillator manufacturer);
b) if the patient is conscious, apply sedation or analgesia.

3) Tachycardia with a narrow complex, irregular – stable (atrial fibrillation, atrial flutter, multifocal atrial tachycardia):

a) diltiazem 0.25 mg/kg IV over 2 minutes:

• • • • a second dose of diltiazem 0.35 mg/kg IV can be administered if necessary after 15 minutes;
      • for patients over 65 years of age, the recommended maximum initial dose of diltiazem is 10 mg IV and the maximum repeated dose is 20 mg;

b) metoprolol 5 mg IV over 1-2 minutes, the procedure can be repeated if necessary every 5 minutes, the maximum number of doses is 3.

4) Tachycardia with a narrow complex, irregular – unstable:

a) perform a synchronized electrical cardioversion (follow the recommendations of the device manufacturer);
b) if the patient is conscious, apply sedation or analgesia.

5) Tachycardia with a wide complex, regular – stable (ventricular tachycardia, supraventricular tachycardia, atrial fibrillation, atrial flutter with aberrations, accelerated idioventricular rhythm, tachycardia with premature ventricular excitation syndrome):

a) amiodarone 150 mg IV over 10 minutes, a second dose is allowed;
b) procainamide 20-50 mg/min until the arrhythmia stops, or until the systolic pressure drops to 90 mmHg, or until the QRS complex is prolonged (duration increases) by more than 50% or until the maximum dose of 17 mg/kg is administered:

• • • • infusion (administration) rate 1-4 mg/min;
      • avoid using procainamide in the presence of long QT syndrome or HF;

c) lidocaine 1-1.5 mg/kg IV, repeated administration is allowed at 5-minute intervals and a maximum dose of 3 mg/kg;
d) adenosine 6 mg IV followed by 10 ml of saline (bolus), if monomorphic tachycardia continues, administer 12 mg of adenosine IV.

6) Tachycardia with a wide complex, regular – unstable:

a) perform a synchronized electrical cardioversion (follow the recommendations of the defibrillator manufacturer);
b) if the patient is conscious, apply sedation or analgesia.

7) Tachycardia with a wide complex, irregular – stable (atrial fibrillation with aberration, atrial fibrillation (with an additional pathway for electrical impulse conduction), or polymorphic ventricular tachycardia/pirouette ventricular tachycardia:

a) procainamide 20-50 mg/min until the arrhythmia stops or until the systolic pressure decreases to 90 mmHg, or until the QRS complex length increases by more than 50%, or until the maximum dose of 17 mg/kg is administered:

• • • • nfusion rate 1-4 mg/min;
      • avoid using procainamide in the presence of long QT syndrome or HF;

b) in case of atrial flutter, administer magnesium sulfate IV in a dose of 1-2 g over 10 minutes;
c) amiodarone 150 mg IV over 10 minutes:

• • • • the same dose may be repeated if necessary;
      • administration of amiodarone after procainamide is mandatory (if necessary) for patients with Wolff-Parkinson-White syndrome.

8) Tachycardia with a wide complex, irregular – unstable:

a) perform a synchronized electrical cardioversion (follow the recommendations of the defibrillator manufacturer);
b) if the patient is conscious, apply sedation or analgesia.

2. Management of children

2.1. Control of the airway (if necessary).
2.2. Conducting (if necessary) oxygen therapy to achieve saturation in the range of 94-98%.
2.3. Monitoring of vital signs and recording of ECG in 12-leaders.
2.4. Intravenous access.
2.5. Check blood glucose levels and treat hypoglycemia according to the guideline “Hypoglycemia”.
2.6 Remember to apply the following additional therapeutic measures if symptoms of tachycardia or hemodynamic instability persist:

1) Tachycardia with a narrow complex, regular -stable:

a) perform vagal tests;
b) adenosine 0.1 mg/kg (maximum dose – 6 mg), if this does not have an effect, repeat the procedure, increasing the dose to 0.2 mg/kg (maximum 12 mg).

2) Tachycardia with a narrow complex, regular – unstable:

a) perform synchronized electrical cardioversion – 0.5-1 J/kg for the first dose;
b) repeated doses should be 2 J/kg.

3) Tachycardia with a wide complex, regular – stable:

a) use adenosine 0.1 mg/kg (maximum dose – 12 mg) for supraventricular tachycardia with aberrations;
b) otherwise, administer amiodarone 5 mg/kg (maximum dose – 150 mg) for 10 minutes.

4) Tachycardia with a wide complex, regular – unstable

Synchronized electrical cardioversion – 0.5-1 J/kg.

Useful information for training

Key points

1. Causes:

a) hypovolemia;
b) hypoxia;
c) acidosis
d) myocardial infarction;
e) hypo-/hyperkalemia;
f) hypoglycemia;
g) hypothermia;
h) exposure to toxic substances/overdose;
i) blockage;
j) tension pneumothorax;
k) pulmonary or cardiac thrombosis;
l) trauma;
m) hyperthyroidism.

2. Atrial fibrillation rarely requires cardioversion in the field. If it is difficult to determine the onset of arrhythmia, it is necessary to remember about possible thrombosis (before cardioversion).

3. In case of regular tachycardia with a wide complex, one should suspect the syndrome of premature ventricular excitation; such patients require maximum care during the provision of care:

a) characteristic ECG findings are shortened PQ interval and, in some cases, delta waves;
b) Avoid the use of atrioventricular node blockers such as adenosine, calcium channel blockers, digoxin, and beta-blockers in patients with premature ventricular torsades de pointes (i.e., Wolff-Parkinson-White syndrome and Laun-Ganong-Levine syndrome), as these drugs may cause a paradoxical increase in ventricular contractions;
c) blocking of the atrioventricular node in some patients can lead to a situation where electrical impulses will go down exclusively through an additional pathway, and this, in turn, will lead to ventricular fibrillation;
d) amiodarone or procainamide may be used as an alternative during treatment.

4. Amiodarone or procainamide can be used to control heart rate in patients who are not sensitive to other drugs or if they do not have the desired effect, such as patients with congestive heart failure who do not respond to diltiazem or metoprolol.

Particular attention should be paid to patients who do not take anticoagulants, as amiodarone may cause cardioversion.

5. Administer metoprolol to patients with systolic blood pressure above 120 mm Hg.

When using metoprolol, the condition may worsen in congestive heart failure, chronic obstructive pulmonary disease, asthma, as well as hypotension and bradycardia.

6. It has been proven that a biphasic defibrillator transforms atrial fibrillation at a lower charge and is more successful than a monophasic defibrillator.

A gradual increase in the dose (70, 120, 150, 170 J for a biphasic defibrillator and 100, 200, 300, 360 J for a monophasic defibrillator) is recommended, rather than using the maximum charge at once.

7. Studies in children have shown the effectiveness of adenosine in the treatment of hemodynamically stable or unstable supraventricular tachycardia.

8. Adenosine should be used as a priority drug in the treatment of stable supraventricular tachycardia:

a) Verapamil can be considered as an alternative in older children, but should not be used in infants;
b) in case of resistant supraventricular tachycardia, use procainamide or amiodarone by slow intravenous injection under close monitoring of the patient’s hemodynamics.

Relevant assessment findings

No recommendations.

Patient safety

1. Use only one antiarrhythmic drug at a time.
2. Patients receiving metoprolol or diltiazem have a serious risk of hypotension and bradycardia.
3. When using cardioversion, remember about sedation and anesthesia.
4. In case of irregular tachycardia with wide complexes (atrial fibrillation with aberration, such as in Wolf-Parkinson-White and Laun-Ganong-Levin syndrome), avoid the use of atrioventricular node blockers (adenosine, calcium channel blockers, beta-blockers).
5. Patients with Wolff-Parkinson-White syndrome should first receive procainamide and only then amiodarone.

Key elements of documentation

1. Primary rhythm and all its changes.
2. Time, dosage, and response to the drug.
3. Cardioversion time, synchronization, number of attempts, joules, and response.
4. ECG readings after each cardioversion.
5. Patient weight.
6. Patient weight and height (for children).
7. Information about events that may be required during treatment.

Criteria for the effectiveness of care

1. The time it took for the symptoms to improve from the moment of initial contact with the patient.
2. Obtaining blood sugar readings.
3. Using the right medications and dosages for the patient’s condition, age, and weight.
4. Using the correct energy (in joules) during cardioversion based on the patient’s weight and/or condition.
5. Use of pain medications for conscious patients