What to do with a patient getting discharged with no cardiac symptoms, sinus rhythm with premature atrial complexes (PACs), left axis deviation, and a borderline electrocardiogram (ECG)?

Management of Asymptomatic Patient with Sinus Rhythm, PACs, Left Axis Deviation, and Borderline ECG

For a patient with no cardiac symptoms being discharged with sinus rhythm, premature atrial complexes (PACs), left axis deviation, and a borderline ECG, no specific intervention or additional cardiac workup is necessary at this time. 1

Understanding the ECG Findings

Premature Atrial Complexes (PACs)

PACs are common findings on ECG and are generally benign in asymptomatic individuals. They represent early beats originating from the atria and are characterized by:

• Premature P waves with morphology different from sinus P waves
• May be conducted normally, with aberrancy, or blocked
• Often occur in isolation or in patterns such as bigeminy

Left Axis Deviation

Left axis deviation is classified as a borderline ECG finding in athletes and general population 1. It is defined as:

• QRS axis between -30° and -90°
• Common finding that may be a normal variant or associated with left anterior fascicular block
• By itself, not indicative of pathology requiring intervention in asymptomatic individuals

Borderline ECG

According to guidelines, borderline ECG findings in isolation likely do not represent pathologic cardiovascular disease 1. These include:

• Left axis deviation
• Left atrial enlargement
• Right axis deviation
• Right atrial enlargement
• Complete right bundle branch block

Clinical Decision Making

Risk Stratification

1. Low Risk Features (all present in this case):

   • Asymptomatic patient
   • Sinus rhythm as baseline
   • Isolated PACs without sustained arrhythmias
   • Borderline ECG findings without abnormal repolarization
   • No history of cardiac symptoms

2. Evidence for Conservative Management:

   • Recent research shows that even high PAC burden was not associated with increased risk of stroke or death in patients with mild to moderate ischemic stroke 2
   • Guidelines indicate that routine use of antiarrhythmic agents for asymptomatic premature complexes is not justified 1

Management Approach

Immediate Management

• No specific cardiac intervention is needed at discharge
• No antiarrhythmic medications are indicated for asymptomatic PACs 1
• No need for immediate additional cardiac testing

Follow-up Recommendations

• Regular primary care follow-up
• Patient education regarding symptoms that would warrant reassessment:
  • Development of palpitations
  • Syncope or pre-syncope
  • Chest pain
  • Dyspnea
  • Exercise intolerance

When to Consider Additional Evaluation

Additional cardiac evaluation would be warranted if:

1. Patient develops cardiac symptoms
2. ECG changes progress to include pathological findings such as:
   • Pathologic Q waves
   • ST-segment depression (≥0.5 mm in depth in two or more contiguous leads)
   • T-wave inversions in specific lead patterns
   • Ventricular arrhythmias

Pitfalls to Avoid

1. Overdiagnosis and Overtreatment:

   • Avoid unnecessary antiarrhythmic medications for asymptomatic PACs
   • Recognize that isolated left axis deviation and PACs are often benign findings

2. Underestimation of Significant Findings:

   • Ensure that the "borderline ECG" does not contain other pathologic findings that would require intervention
   • Verify that PACs are not triggering sustained arrhythmias

3. Failure to Educate the Patient:

   • Patients should understand which symptoms would warrant seeking medical attention
   • Clear discharge instructions regarding follow-up are essential

In conclusion, while PACs, left axis deviation, and borderline ECG findings may raise concern, current evidence supports that these findings in an asymptomatic patient do not require specific intervention at discharge. The patient can be safely discharged with appropriate follow-up instructions.