Monday, June 22, 2015

Key differences between coronary angiography and IVUS ( Intra-vascular ultrasound )

Angiography shows only the silhouette of contrast media flowing through a lumen. IVUS shows us much more diagnostic information:
•Measurable extent of stent apposition and expansion.
•Measurable size and shape of lumen, plaque, intima and media.
•Shape and composition of intima, media and adventitia.
•Differentiation among fibrous, fibro-fatty and calcified plaque.
•Positive identification of blood.

Thursday, June 18, 2015

What is Twiddler syndrome?

   Displacement of pacemaker leads due to twisting  of the box on part of the patient is called
   Twiddler’s syndrome, first described in 1968  (Nicholson et al., 2003).Twiddler syndrome
    that causes device malfunction is a rare complication in patients with an implantable      cardioverter    defibrillators (ICD) (Fahraeus & Höijer, 2003). Twisting of the pulse generator
    within the device pocket may cause the dislocation of the lead, diaphragmatic stimulation,
    and loss of capture (Figure 7). The prevelance  of this syndrome is 0.07% (Gungor et al.,
    2009). Classically, Twiddler syndrome occurs in obese women with loose, fatty
    subcutaneous tissue and is characterized by rotate on of pulse generator on its long axis with       subsequent coiling of pacemaker leads (Bhatia et al., 2007). Other risk factors are mental  disorders,     female sex, and the small size of the implanted generator with a large pocket  (Cardall et   al., 1999). This disorder may induce lead dislodgement or lead fracture and cause  life-threatening  symptoms in case of pacemaker dependency. When the pulse generator is  rotated    along the transverse axis it is referred by us as the Reel syndrome, a variant of  Twiddler syndrome (Camero-Varo et al., 1990). 

In Twiddler syndrome, electrocardiography shows failure of capture and the chest
radiography reveals the dislodged and twisted  leads (Pereira et al., 1999). Hypoperfusion  symptoms such as fatigue, tiredness, confusion, presyncope, and syncope may be obse
rved  (Cardall et al., 1999). If the problem has occured because of pacemaker migration or poorly  fashioned pacemaker pocket, the pocket should be revised. As an inappropriate ICD
therapy may be proarrhythmic and may lead to sudden cardiac death, Twiddler syndrome
should be considered in patients with ICD  who had resistant ventricular arrhythmias and
abdominal pulsation. To avoid this life-threatening complication of ICD implantation, we
should take care to limit the pocket size, suture the device to the fascia, and instruct the
patients not to manipulate their device pockets. 

Pacemaker Twiddler syndrome. Postero-anterior and lateral chest X-ray showing
displacement of both leads, especially the ventricle one, retracted and floating in the right
atrium (arrows).