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Looks like VT But Isn't--successful ablation of a left free wall accessory pathway with Mahaim-like properties.

Osman F, Stafford PJ, Ng GA - Indian Pacing Electrophysiol J (2009)

Bottom Line: We report a patient who presented with a broad complex tachycardia thought to be ventricular tachycardia; however during EP study this was shown to be an antidromic atrioventricular tachycardia utilising a left free wall pathway that demonstrated 'Mahaim-like' properties and was successfully ablated.The pathway was shown to have long conduction times with no retrograde conduction, had an effective refractory period longer than the AV node and its conduction was only evident during antidromic AVRT.These 'Mahaim-like' features are very unusual and rarely reported on the left side.

View Article: PubMed Central - PubMed

Affiliation: University Hospital Coventry, Department of Cardiology, Clifford Bridge Rd, Coventry CV22DX. faizel.osman@btinternet.com

ABSTRACT
It was long believed that Mahaim pathways represented nodo-fascicular or nodo-ventricular connections. However, this misconception was challenged when patients underwent surgical or catheter ablation of the AV node but remained pre-excited. Electrophysiology (EP) studies showed these pathways to be right sided decrementally conducting atrio-fascicular accessory pathways with the atrium forming a part of the antidromic tachycardia circuit. Mahaim pathways are usually reported to occur on the right side. We report a patient who presented with a broad complex tachycardia thought to be ventricular tachycardia; however during EP study this was shown to be an antidromic atrioventricular tachycardia utilising a left free wall pathway that demonstrated 'Mahaim-like' properties and was successfully ablated. The pathway was shown to have long conduction times with no retrograde conduction, had an effective refractory period longer than the AV node and its conduction was only evident during antidromic AVRT. It also had a decremental antegrade property and was responsive to intravenous adenosine. These 'Mahaim-like' features are very unusual and rarely reported on the left side.

No MeSH data available.


Related in: MedlinePlus

Resting 12-lead ECG showing broad complex tachycardia
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F1a: Resting 12-lead ECG showing broad complex tachycardia

Mentions: A 44-year old woman presented with a two hour history of sudden onset palpitation while walking her dog but no syncope. She had no significant past medical history of note but a paternal uncle had died suddenly at the age of 50 years and her father had been diagnosed as having cardiomyopathy and had an implantable cardioverter defibrillator implanted several years previously. She was taking no regular medication. On arrival into hospital she had a blood pressure of 110/60 mmHg and pulse rate of 215 beats per minute; there were no signs of cardiac failure. A resting 12-lead electrocardiogram (ECG) revealed a regular broad complex tachycardia, which was diagnosed as ventricular tachycardia (Figure 1a); this diagnosis was based on previously reported criteria [1]. The patient reverted to sinus rhythm spontaneously and repeat 12-lead ECG revealed no abnormalities (Figure 1). Transthoracic echocardiography and exercise tolerance test were normal. Coronary angiography and cardiac magnetic resonance imaging scan were also normal.


Looks like VT But Isn't--successful ablation of a left free wall accessory pathway with Mahaim-like properties.

Osman F, Stafford PJ, Ng GA - Indian Pacing Electrophysiol J (2009)

Resting 12-lead ECG showing broad complex tachycardia
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2655058&req=5

F1a: Resting 12-lead ECG showing broad complex tachycardia
Mentions: A 44-year old woman presented with a two hour history of sudden onset palpitation while walking her dog but no syncope. She had no significant past medical history of note but a paternal uncle had died suddenly at the age of 50 years and her father had been diagnosed as having cardiomyopathy and had an implantable cardioverter defibrillator implanted several years previously. She was taking no regular medication. On arrival into hospital she had a blood pressure of 110/60 mmHg and pulse rate of 215 beats per minute; there were no signs of cardiac failure. A resting 12-lead electrocardiogram (ECG) revealed a regular broad complex tachycardia, which was diagnosed as ventricular tachycardia (Figure 1a); this diagnosis was based on previously reported criteria [1]. The patient reverted to sinus rhythm spontaneously and repeat 12-lead ECG revealed no abnormalities (Figure 1). Transthoracic echocardiography and exercise tolerance test were normal. Coronary angiography and cardiac magnetic resonance imaging scan were also normal.

Bottom Line: We report a patient who presented with a broad complex tachycardia thought to be ventricular tachycardia; however during EP study this was shown to be an antidromic atrioventricular tachycardia utilising a left free wall pathway that demonstrated 'Mahaim-like' properties and was successfully ablated.The pathway was shown to have long conduction times with no retrograde conduction, had an effective refractory period longer than the AV node and its conduction was only evident during antidromic AVRT.These 'Mahaim-like' features are very unusual and rarely reported on the left side.

View Article: PubMed Central - PubMed

Affiliation: University Hospital Coventry, Department of Cardiology, Clifford Bridge Rd, Coventry CV22DX. faizel.osman@btinternet.com

ABSTRACT
It was long believed that Mahaim pathways represented nodo-fascicular or nodo-ventricular connections. However, this misconception was challenged when patients underwent surgical or catheter ablation of the AV node but remained pre-excited. Electrophysiology (EP) studies showed these pathways to be right sided decrementally conducting atrio-fascicular accessory pathways with the atrium forming a part of the antidromic tachycardia circuit. Mahaim pathways are usually reported to occur on the right side. We report a patient who presented with a broad complex tachycardia thought to be ventricular tachycardia; however during EP study this was shown to be an antidromic atrioventricular tachycardia utilising a left free wall pathway that demonstrated 'Mahaim-like' properties and was successfully ablated. The pathway was shown to have long conduction times with no retrograde conduction, had an effective refractory period longer than the AV node and its conduction was only evident during antidromic AVRT. It also had a decremental antegrade property and was responsive to intravenous adenosine. These 'Mahaim-like' features are very unusual and rarely reported on the left side.

No MeSH data available.


Related in: MedlinePlus