| Fact | Explanation |
|---|---|
| Blackouts [1] | In Lown-Ganong-Levine syndrome, normal conduction of electrical impulses through the heart is bypassed from aberrant conduction pathway which results in heart rhythm disturbances that leads to intermittent episodes of rapid heart rates.These episodes may lead to blackouts [1] |
| Palpitations [4] | Heart rhythm disturbances that leads to intermittent episodes of rapid heart rates may lead to palpitations [1] |
| Faintness/ light headedness [5] | Heart rhythm disturbances that leads to intermittent episodes of rapid heart rates lead to faintness [1] |
| Congenital heart defects [3] | Congenital defects in the conduction system can give rise to Lown-Ganong-Levine syndrome [3] eg : hypertrophic cardiomyopathy, Ebstein’s anomaly, tricuspid atresia [5] |
| Fact | Explanation |
|---|---|
| Tachycardia [1] | In Lown-Ganong-Levine syndrome, normal conduction of electrical impulses through the heart is bypassed from aberrant conduction pathway which results in heart rhythm disturbances that leads to intermittent episodes of rapid heart rates.These episodes may lead to tachycardia ( supraventricular tachycardia ) [2] The diagnosis is based on identifying paroxysms of rapid heart rate [3] |
| Low blood pressure [2] | The presence of an anomalous conducting pathway would account for the recurrent disorder of cardiac rhythm, associated with hypotension [2] |
| Accentuated first heart sound [3] | There is an accentuated first heart sound in most patients due to short PR interval [3] |
| Normal physical examination [1] | As these changes are episodic, patient will be completely normal in between the episodes [1] |
| Fact | Explanation |
|---|---|
| Wolff-Parkinson-White syndrome [1] | Delta waves in Wolff-Parkinson-White syndrome are absent in Lown-Ganong-Levine syndrome [1] |
| Other Supraventricular tachycardias- AV Nodal Re-entry Tachycardia [2] | Diagnosis of Lown-Ganong-Levine syndrome is primarily by excluding other arrhythmias by an ECG [1] AV Nodal Re-entry Tachycardia : Rate: 118 to 264 bpm Rhythm: regular, narrow QRS complex (< 120 msec); regular, wide QRS complex (≥ 120 msec); may not see any P-wave activity in either type (atypical or typical) Atypical AVNRT: RP interval > PR interval; P waves negative in leads III and aVF Typical AVNRT: RP interval < PR interval; pseudo R wave in lead V1 with tachycardia, not with normal sinus rhythm; pseudo S wave in leads I, II, and aVF [2] |
| Other Supraventricular tachycardias- Atrioventricular reciprocating tachycardia [2] | Diagnosis of Lown-Ganong-Levine syndrome is primarily by excluding other arrhythmias by an ECG [1] Rate: 124 to 256 bpm Rhythm: regular, narrow QRS complex common (orthodromic); regular, wide QRS complex uncommon (orthodromic or antidromic) if bundle branch block or aberrancy present Orthodromic AVRT: RP interval < PR interval or RP interval > PR interval with a slowly conducting accessory pathway; retrograde P waves (leads I, II, III, aVF, V1); delta wave seen with normal sinus rhythm, not with tachycardia Antidromic AVRT: short RP interval (< 100 msec); regular, wide QRS complex (≥ 120 msec); delta waves seen with normal sinus rhythm and tachycardia; concealed accessory pathways do not show delta waves [2] |
| Other Supraventricular tachycardias- atrial tachycardia [2] | Diagnosis of Lown-Ganong-Levine syndrome is primarily by excluding other arrhythmias by an ECG [1] Rate: 100 to 250 bpm (atrial); ventricular varies Rhythm: regular, narrow QRS complex usually; irregular (ectopic foci) may have wide QRS complex if aberrancy present Focal AT: long RP interval most common; P-wave shape/polarity variable Multifocal AT: three different P-wave morphologies exist unrelated to each other; RR interval irregularly [2] |
| Ventricular tachycardia [3] | Diagnosis of Lown-Ganong-Levine syndrome is primarily by excluding other arrhythmias by an ECG [1] Wide QRS complexes, Rate >100 (most commonly 150–200), Rhythm is usually regular, although there may be some beat-to-beat variation, QRS axis is usually constant [3] |
| Ventricular fibrillation [4] | Diagnosis of Lown-Ganong-Levine syndrome is primarily by excluding other arrhythmias by an ECG [1] ECG findins of Ventricular fibrillation - Chaotic irregular deflections of varying amplitude No identifiable P waves, QRS complexes, or T waves Rate 150 to 500 per minute [4] |
| Fact | Explanation |
|---|---|
| Electrocardiogram (ECG) [1] | PR interval less or equal to 0.12 second (120 ms) with normal QRS complex duration.ECG may show episodes of supraventricular tachycardia. The tachycardia can be corrected by vagal maneuvers. [1] |
| Holter monitoring [1] | Holter monitoring may be needed in some patients to identify the paroxysms. [1] |
| Fact | Explanation |
|---|---|
| Lipid profile [1] | The greatest harm in the care of these patients is the frequent attribution of coronary artery or arteriosclerotic heart disease as the cause of the recurrent tachycardia,Thus assessing the lipid profile is important. Recommended low-density lipoprotein cholesterol target level in people with heart disease <100 mg/dl [1] |
| Fasting blood sugar [1] | Controlling of other co morbid conditions is important as the greatest harm in the care of these patients is the frequent attribution of coronary artery or arteriosclerotic heart disease as the cause of the recurrent tachycardia [1] |
| Fact | Explanation |
|---|---|
| Electrocardiogram [1] | PR interval less or equal to 0.12 second (120 ms) with normal QRS complex duration.ECG may show episodes of supraventricular tachycardia [1] |
| Serum electrolytes [1] | To verify that the electrolytes are normal,as abnormalities in electrolytes can give rise to similar symptoms such as faintness [1] |
| Lipid profile [1] | The greatest harm in the care of these patients is the frequent attribution of coronary artery or arteriosclerotic heart disease as the cause of the recurrent tachycardia,Thus assessing the lipid profile is important [1] |
| Fact | Explanation |
|---|---|
| Electrocardiogram (ECG) [1] | PR interval less or equal to 0.12 second (120 ms) with normal QRS complex duration.ECG may show episodes of supraventricular tachycardia [1] |
| Serum electrolytes [1] | To verify that the electrolytes are normal,as abnormalities in electrolytes can give rise to similar symptoms such as faintness [1] |
| Fact | Explanation |
|---|---|
| Controlling other co morbid conditions [1] | The greatest harm in the care of these patients is the frequent attribution of coronary artery or arteriosclerotic heart disease as the cause of the recurrent tachycardia [1] |
| Avoid triggering factors [1] | Avoid emotional stresses [1] |
| Fact | Explanation |
|---|---|
| Digoxin [1] | Reduces the heart rate [1] |
| Beta blockers [1] | They act by blocking the effects of catecholamines at the β1-adrenergic receptors, thereby decreasing sympathetic activity on the heart. These agents are particularly useful in the treatment of supraventricular tachycardias as they decrease conduction through the atrio ventricular (AV) node [1] |
| Calcium channel blockers [1] | They decrease conduction through the AV node, and shorten phase two (the plateau) of the cardiac action potential [1] |
| Surgical management - pacemaker implantation, followed by radiofrequency (RF) ablation of the AV node [1] | For patients with failed medical therapy who continue to have recurrent, intolerable symptoms [1] |