The severity of symptoms in patients with PSVT depends on any underlying structural heart disease, the frequency of PSVT episodes, and the patient's hemodynamic reserve. Usually, patients with PSVT present with symptoms of dizziness, syncope, nausea, shortness of breath, intermittent palpitations, pain or discomfort in the neck, pain or discomfort in the chest, anxiety, fatigue, diaphoresis, and polyuria secondary atrial natriuretic factor secreted mainly by the heart's atria in response to atrial stretch. The most common symptoms are dizziness and palpitations. Patients with PSVT and a known history of coronary artery disease may present with a myocardial infarction secondary to the stress on the heart. Patients with PSVT and a known history of heart failure may come in with acute exacerbation. Frequent PSVTs in a patient can result in new-onset of heart failure secondary to tachycardia-induced cardiomyopathy.[16]

A detailed history of the patient with PSVT should include past medical and cardiac history, time of symptom onset, prior episodes, and treatments. The patients' current medication list must be obtained. Investigations of involvement in physical activities such as exercise or outdoor sports should be made, as patients who have symptomatic PSVT's avoid such hobbies. Patients presenting with PSVTs should get a thorough physical exam, including vital signs (respiratory rate, blood pressure, temperature, and heart rate) to help assess their hemodynamic stability.[17]

A significant component of evaluation for a patient who presents with signs and symptoms of PSVT is history and physical exam. These should include vital signs (respiratory rate, blood pressure, temperature, and heart rate), review of the patient's medication list, and a 12-lead electrocardiogram. During an evaluation, a health care provider should establish if the patient is hemodynamically stable and whether they have any underlying ischemic heart disease or heart failure. Digoxin toxicity should be ruled out.

Healthcare providers should consider thyroid function testing, pulmonary function testing, including routine blood work, and echocardiography as part of their initial evaluation of patients presenting with symptomatic PSVTs.[18][19]

ECG features:

1. Sinus tachycardia with a heart rate more than 100 bpm with normal P waves
2. Atrial tachycardia with a heart rate between 120-150 bpm. The P wave morphology may be different from normal sinus rhythm
3. Multifocal atrial tachycardia with heart rates from 120-200 bpm with 3 or more different P wave morphologies
4. Atrial flutter with a heart rate of 200-300 bpm
5. Atrial fibrillation with irregularly irregular rhythm and no visible P waves
6. AVNRT with a heart rate of 150-250 bpm, P waves before or within the QRS complex, short PR interval
7. AVRT with a heart rate between 150-250 bpm, narrow QRS complex in orthodromic conduction and wide QRS complex in antidromic conduction

Treatment of PSVT in a patient is dependent on the type of rhythm present on the electrocardiogram and the patient's hemodynamic stability. Patients presenting with hypotension, shortness of breath, chest pain, shock, or altered mental status are considered hemodynamically unstable, and their electrocardiogram evaluation must be done to determine if they are in sinus rhythm or not. If they are not in sinus rhythm, these patients should undergo urgent cardioversion. If they are determined to be in appropriate sinus tachycardia, then their underlying etiology must be treated. For any manifestations of cardiac ischemia, intravenous beta-blockers should be considered. If they have inappropriate sinus tachycardia on the electrocardiogram and are determined to be hemodynamically unstable, treatment with intravenous beta-blockers may be appropriate.[20][21][22]

If on the initial evaluation, a patient is to found to be hemodynamically stable, then the treatment of the patient depends on the specific PSVT present on the electrocardiogram. If the 12-lead electrocardiogram shows that the rhythm is irregular and P waves are absent, then the patient should be appropriately treated for atrial fibrillation. If the rhythm on the electrocardiogram is irregular and flutter waves are present, then the patient should be treated for atrial flutter. If the rhythm on the electrocardiogram is irregular and multiple P wave morphologies are present, then the patient should be treated for multifocal atrial tachycardia.[23]

In patients who are hemodynamically stable and showing a regular rhythm with visible P waves on the electrocardiogram, then an assessment of the atrial rate, the relationship between the atrial and ventricular pacing, P-wave morphology and the P-wave position in the rhythm cycle is required. Type of PSVT present (atrial tachycardia, multifocal atrial tachycardia, atrial flutter, atrial flutter with a variable block, intra-atrial reentrant tachycardia, sinus tachycardia, sinoatrial node reentrant tachycardia, atrioventricular nodal reentrant tachycardia, atrioventricular reciprocating tachycardia, junctional ectopic tachycardia, and nonparoxysmal junctional tachycardia) determines the treatment.[24][25]

In patients who are hemodynamically stable and have an electrocardiogram that shows a regular rhythm with undetectable P waves, Valsalva maneuvers, carotid sinus massage, or intravenous adenosine might be used to slow the ventricular rate or convert the rhythm into sinus rhythm and thus aid in the diagnosis. In some instances, increasing the electrocardiogram paper speed from 25 mm per second to 50 mm per second might help as well. If intravenous adenosine does not work, then intravenous or oral calcium channel blockers or beta-blockers should be used. Patients with PSVTs must also undergo evaluation for any underlying pre-excitation syndrome, and patients who fail medical treatment or those who might need radiofrequency catheter ablation need cardiology consultation.[26][27][28]

The differential includes: [29][30]

• Atrial tachycardia
• Multifocal atrial tachycardia (MAT)
• Atrial flutter
• Atrial flutter with variable block
• Atrial fibrillation
• Intraatrial reentrant tachycardia
• Sinus tachycardia
• Inappropriate sinus tachycardia
• Sinoatrial node reentrant tachycardia
• Atrioventricular nodal reentrant tachycardia
• Atrioventricular reciprocating (reentrant) tachycardia
• Junctional ectopic tachycardia
• Nonparoxysmal junctional tachycardia

In cases with no structural heart disease, the prognosis of PSVT is reasonably good. For patients with structural heart disease, the prognosis is often guarded. The arrhythmia may come on suddenly and last anywhere from a few seconds to several days. Most patients develop anxiety, a sense of doom, and others may develop hemodynamic compromise. The arrhythmia can result in congestive heart failure, myocardial infarction, and pulmonary edema.

If not identified promptly symptomatic complications such as syncope, fatigue, or dizziness can occur. 

Educating patients at risk for this rhythm and making a closed-loop communication between them and their providers can help further improve the management of these rhythms. If available, patient education should be provided using resources familiar to the patient including online resources and pamphlets. 

Frequent PSVT can result in tachycardia-induced cardiomyopathy, a study on pregnant females found that PSVT in the first to second gestational month increase the chances of the child developing ostium secundum atrial septal defect.

Treatment of PSVT can involve an interprofessional team, including emergency department physicians and nurses, cardiologists and cardiology nurses, primary care providers, and pharmacists. Emergency medical technicians are often the first to encounter patients and provide treatment. The team should evaluate, as outlined above. Nurses, pharmacists, and physicians can provide education. Pharmacists should educate patients about medication side effects and compliance, as well as checking for drug interactions. [Level 5]