Pulseless Ventricular Tachycardia (PVT) is a sudden, life-threatening electrical malfunction within the heart’s ventricles. The ventricles contract at an extremely rapid rate, but the contractions are so disorganized that the heart cannot effectively pump blood to the body. This results in the complete absence of a palpable pulse and immediate cardiac arrest. Since blood flow ceases to the brain and other organs, death is imminent, making immediate intervention the only possibility for survival. Successful treatment relies on Advanced Cardiac Life Support (ACLS), performed without delay by trained medical professionals.
Immediate Lifesaving Steps: CPR and Defibrillation
Treatment for pulseless cardiac arrest begins immediately with high-quality Cardiopulmonary Resuscitation (CPR) while a defibrillator is prepared. High-quality chest compressions manually push blood to the brain and coronary arteries, maintaining organ perfusion until the heart’s rhythm can be restored. Compressions must be delivered at a rate between 100 and 120 per minute, with a depth of at least two inches (five to six centimeters). Full chest recoil is permitted after each compression, and interruptions must be minimized to maintain consistent blood flow.
PVT is a “shockable” rhythm, meaning the chaotic electrical activity can be terminated by an electrical shock. Once the defibrillator is attached, the team analyzes the rhythm, and if PVT is confirmed, a shock is delivered immediately. Modern biphasic defibrillators typically deliver a first shock between 120 and 200 Joules, or the maximum energy available if the dose is unknown.
The electrical shock is the primary treatment for PVT, aiming to reset the heart’s electrical system. Immediately after the shock is delivered, CPR must be resumed for a full two-minute cycle without pausing for a pulse check. This continuous cycle of CPR circulates the oxygen and energy needed for the heart muscle to respond to the next intervention. After the two minutes are complete, the rhythm is re-analyzed. A pulse check is performed only if the rhythm appears organized and capable of generating a heartbeat.
Medication Management (The Vasopressor and Antiarrhythmic Cycle)
Pharmacological intervention is integrated into the two-minute CPR and shock cycles, starting with a vasoconstrictor medication. Epinephrine is the standard vasopressor, administered as a one-milligram dose intravenously or intraosseously every three to five minutes. Epinephrine causes peripheral vasoconstriction, increasing the pressure gradient in the major arteries. This improves perfusion pressure to the brain and heart muscle, making subsequent defibrillation attempts more effective.
If PVT persists after the second shock and the first dose of Epinephrine, an antiarrhythmic agent is introduced. Antiarrhythmics stabilize the electrical excitability of cardiac cell membranes to prevent the recurrence of the disorganized rhythm. The preferred agent is Amiodarone, administered as a 300-milligram bolus after the third shock, provided the rhythm remains shockable.
If PVT remains refractory to initial therapy, a second, smaller dose of Amiodarone (150 milligrams) can be given after a subsequent two-minute CPR cycle. If Amiodarone is unavailable, an alternative antiarrhythmic like Lidocaine may be used, with an initial dose ranging from 1.0 to 1.5 milligrams per kilogram of body weight. The staggered timing ensures the drugs circulate and act within the heart muscle between CPR and defibrillation attempts. This sequence of compressions, shocks, vasopressors, and antiarrhythmics forms the core of the advanced management algorithm.
Identifying and Treating Underlying Causes
While immediate resuscitation focuses on electrical and mechanical treatment, successful long-term recovery requires diagnosing and correcting any underlying physiological cause. Rescuers simultaneously investigate potential reversible factors that may have triggered the arrest. These factors are commonly grouped into categories related to oxygenation, volume, and mechanical interference.
Reversible Causes (H’s and T’s)
Conditions such as severe lack of oxygen (hypoxia) or massive blood loss (hypovolemia) must be swiftly identified and corrected with ventilation or fluid replacement. Other causes include severe electrolyte disturbances, such as potassium imbalances, and profound core body temperature reduction (hypothermia). These chemical or thermal problems destabilize the heart’s electrical system and must be treated concurrently with CPR and drug therapy.
Mechanical and structural issues are also investigated, including a collapsed lung (tension pneumothorax) or fluid accumulation around the heart (cardiac tamponade). These require specific mechanical interventions, such as needle decompression or pericardiocentesis, to relieve pressure. Addressing these underlying causes alongside the continuous resuscitation algorithm is paramount, as the heart cannot maintain a sustainable rhythm if the original trigger remains uncorrected.
Post-Resuscitation Care and Stabilization
Achieving Return of Spontaneous Circulation (ROSC) marks a shift from emergency resuscitation to comprehensive critical care management. Immediate goals following a successful return of a pulse include optimizing ventilation and oxygenation to prevent secondary brain injury. Blood pressure must be carefully stabilized using intravenous fluids and, if necessary, continuous infusions of vasopressors to maintain adequate perfusion to the brain and other organs.
Targeted Temperature Management (TTM) is initiated for patients who remain unresponsive after ROSC. TTM involves maintaining body temperature in a narrow range, typically between 32 and 36 degrees Celsius, for at least 24 hours, or preventing fever by maintaining targeted normothermia. The purpose of this controlled temperature management is to mitigate neurological injury that commonly occurs following cardiac arrest.
Once the patient is stabilized, definitive treatment must address the cause of the PVT. If a heart attack is suspected as the trigger, the patient requires immediate transfer for coronary angiography and potentially percutaneous coronary intervention (PCI) to restore blood flow to the heart muscle. This comprehensive post-arrest care, including advanced monitoring and transfer to a specialized critical care unit, is essential for improving the patient’s chance of functional neurological recovery.