Posted in Cardiology - Electrophysiology -Pacemaker, Cardiology -Funny events, ICD and Pacemakers, tagged cardaic electrophysiology, crazy cardiology, ICD, icd blocks bulllet, icd complication, unusual beenfits of icd on October 31, 2014| Leave a Comment »
We live in curious times .As we advance in our intellect and wisdom ,bullet firings (either cross or straight !) have become an important cause for sudden cardiac death.Sometimes a life is saved by unexpected way in extraordinary circumstances. Here is a man from Florida , whose life was saved by an ICD not by shocking a VF . . . but by blocking a bullet
A case report from Heart Rhythm
Complete Heart Bullet Block : The Aftermath
It seems ICD is strong enough to stop a bullet !
Posted in Cardiology - Electrophysiology -Pacemaker, Cardiology -Interesting videos, Cardiology -Pacemakers and ICD, tagged ICD, implantable cardiovertor defibrillator, Indications for ICD, live icd shock on October 25, 2013| Leave a Comment »
This post , is probably not meant for cardiology professionals.
Few technologies are clear winners in modern medicine. ICDs play games that would rival the God !
What is an ICD ?
Here is a man , who drops almost dead by a fatal cardiac arrhythmia . In few seconds ICD machine recognises this arrhythmia ,charges itself and fires a shock of about 30 joules direct current .The arrhythmia is reverted and the fellow gets up as if nothing has happened !
Watch this video
This revolutionary devices are to be used judiciously in individuals with high risk for dangerous cardiac arrhythmia.
The current indications as on 2012
Reference
Posted in Cardiology - Electrophysiology -Pacemaker, cardiology -ECG, Cardiology-Arrhythmias, Uncategorized, tagged A NEW MEANING FOR SCD, ICD, ICD FOR SCD, scd, subcutaneous icd, subcutaneous icd for sudden cardiac death preventio on September 14, 2010| Leave a Comment »
Implantable cardiovertor defibrillator(ICD) is one of the major revolution in cardiology practice that happened last century. We know , the number one killer of mankind is the ventricular fibrillation induced by acute or chronic CAD.
In the later half of 20th century we learnt that , the only way to prevent a sudden cardiac death is the defibrillating the heart as soon as the deadly killer arrhythmia strikes !
Whenever cardiac arrest happens in a susceptible population , following things are possible.
And now new mode of defibrillation
Transvenous implantation becomes technically complex in many .Abandoning the procedure or using subcutaneous pads are necessary in few . Then , this question was asked
Why not the entire ICD implantation be in subcutaneous plane ?
Yes , it is possible . After all , current can reach the place where it is needed , irrespective of the site it is delivered. The aim of this technique is to simplify the ICD implantation , so that it can be practiced in a wider clinical set up Preliminary results of subcutaneous ICD are available and was published recently in NEJM.
The issues that need to be tackled are
Posted in Cardiology - Clinical, tagged bundle brancg reentry, cardiac arhhythmias, dc shock, defibrillator, ICD, ischemic vt, lvot vt, madit, madit 2, naspe, nstemi, pace, ventricular fibrillation, ventricular tachycardia, vf, vt, vt in unstable angina on May 10, 2009| Leave a Comment »
Acute coronary syndrome is the commonest cardiac emergency. STEMI and NSTEMI are the two clinical limbs of ACS. Generally they have distinct clinical, ECG, angiographic features.(Ofcourse, with some degree of overlap) . It is a mystery , both clinical presentations differ so much inspite of the common denominator , namely , an injured plaque with add on thrombus within the coronary artery. The primary difference between these two entities is, in STEMI the occlusion occurs sudden and complete and in NSTEMI it occurs slow and incomplete
Cardiac arrhythmias in ACS
It is a much published factoid for many decades, that only one third of STEMI patients reach the hospital alive ! The reason being , STEMI is very much prone for primary VF. Contrary to this , most pateints with NSTEMI reach the hospital alive ! How ?
Both are ACS, if ischemia is a powerful trigger for dangerous ventricular arrhythmia’s , NSTEMI should also behave similarly .So what protects against arrhythmias in NSTEMI ?
- We realise , by observational experience (Not EBM !) It is the suddenness and totality of ischemia that trigger dangerous form of arrhythmia .
- Further, a balanced ischemia in two contralateral segments (or global ischemia) some how protects against development of ventricular fibrillation .This may be due to preservation of electrical homogeneity , and the spherical VT spiral waves are not sustainable.
- In contrast , STEMI has a sudden focal , ischemic zone that initiates the VT and ischemia free contralateral segment welcoming and sustaining the reentrant wavelet.
- The observation of primarily single vessel disese in STEMI and multivessel disease in NSTEMI also give credence to this concept.
- Further , ischemic preconditioning can exert an important anti arrhythmic effect in NSTEMI as patients with unstable angina have slow, repetitive episodes of ischemia prior to the index event .
- Post MI scar mediated VT/VF is independent of degree of overall ischemia
- It is also established , a sub group of STEMI pateints who had preinfarction angina( ie . a brief period of UA/NSTEMI) have very low risk of SCD supporting the concept of sensitising the myocardium against ventricular arrhythmias.
Final message
Even though , there is a convincing concept of Ischemia induced cardiac arrhythmia in literature ,in real patients it is very difficult to link the two in many situations..UA/NSTEMI is the most common acute ischemic event but the incidence of VT/VF here, is far less than one would expect.In ACS , focal , total ischemia is more likely to precipitate a VT/VF than multifocal and global ischemia.
Posted in Cardiology - Clinical, cardiology -ECG, Cardiology -unresolved questions, cardiology- coronary care, Cardiology-Arrhythmias, Cardiology-Coronary artery disese, tagged alive study, amiodarone, arrest study, cast study, ccu, ICD, lignocaine, lignociane vs amiodarone, ventricualr tachycardia, xylocard on January 28, 2009| Leave a Comment »
Lignocaine , probably has saved more lifes world over than any other cardiac drug .
It was the only choice for ventricular tachycardia till 1990s, both in pre and post thrombolytic era.Every coornary care unit has reverted tens of thousands of unstable VTs with this simple and cheap intravenous drug.the utility value of lignocaine is not limited to ischemic VT alone it is effective in in almost all forms of VT.It was classically administered in two or more boluses followed by an infusion.
The power of statistics , and inappropriate interpretation by the scientific community has left a serious blow to this wonder drug .Now the drug has been made redundant, and mainstream cardiac literature has made everyone feel guilty , if anybody uses this drug for VT .
CAST study http://content.nejm.org/cgi/content/abstract/321/6/406
All , CAST said was routine suppression of asymptomatic ventricular arrhythmias in the post MI period is unwarranted. But you know , how this world interpreted it “Lignocaine has no role in ventricular arrhythmias in post MI setting ” The most funny thing was lignocine was never used in CAST study .
The studies involving one to one comparison of Lignocaine and Amiodarone (ALIVE and ARREST study) was also not interpreted properly.These studied only shock resistant VTs. What about the role of lignocaine where defibrillator was not available ?
Link to ALIVE and ARREST read and make your own conclusion.
http://content.nejm.org/cgi/content/abstract/346/12/884
http://content.nejm.org/cgi/content/full/341/12/871?ijkey=8fa241f3cebb86a177632ec6ccadfb5a3ded7bc2
Let us take home , the message (scientific or unscientific ! ) Lignocaine still has a great role to play in the management of dangerous ventricular arrhythmias .The only caution is , it should not be used routinely and indiscriminately in all asymptomatic patients with VPDs or nonsustained VT . (Acknowledging CAST conclusion.)
Posted in Cardiology - Electrophysiology -Pacemaker, Cardiology -Interventional -PCI, cardiology -Therapeutics, tagged bmj, cardiac failure, cardiac resynchronisation therapy, care hf, circulation, combo device, CORONARY SINUS, coronary veins, cpmanion, CRT, desynchronisation, echocardiography, electrophysiology, ICD, jama, lancet, lv epicardial pacing, madras medical college, medtronic, miracle, nejm, prospect, resynchronisation, rethinq, st jude, tissue tracking on October 27, 2008| Leave a Comment »
CRT , cardiac resynchronisation therapy is being projected as a revolutionary treatment for cardiac failure , where a failing heart is rewired electrically through multiple leads and make it contract more effectively.The success rate of CRT was highly variable.The basic question here is, there should be a significant documentation of desynchronisation prior to CRT , for resynchronisation to be effective. Further , the sites of myocardial stimulation ( Coronary sinus/LV epicardial) , dose of electricity and the sequence of stimulation and the electrical delay are very critical. Achieving this into perfection is not a simple job and is real rocket science ! ( If we can achieve 5 % of what the normal purkinje network do within the LV we can term it a huge success.) Let us hope we catch up with nature . Finally , it is ironical the sites of LV pacing , electrophysiologists select currently is infact not selected by them but pre selected by the patients coronary venous anatomy ! .So as on date , one can imagine how scientific this treatment could be !
Initially it was adviced for patients with only wide qrs later for even normal qrs patients.When people started using it indiscriminately insurance companies started to rethink and thus came the RETHINQ study in NEJM and brought a full stop to CRT in normal qrs CHF.
It is a million dollar question. So millions of dollars were spent to identify the correct tool to identify the true responders to CRT.Echo cardiography with sophisticated methods tissue doppler, tissue tracking and , 3 D echo ,velocity vector imaging were done .These methods are not only costly but also time consuming and hugely expertise driven.
This simple question was addressed in PROSPECT study in circulation
Posted in Cardiology - Electrophysiology -Pacemaker, tagged diathermy, electrocautery, ICD, pace maker malfunction on June 18, 2008| Leave a Comment »
Patients with permanent pacemaker can have disastrous consequences if inappropriate sensing of external electrical events during surgery. Electro cautery or diathermy should be used judiciously .
1. Aviod diathermy if possible.
2. If neccessary use only bi- polar diathermy .
3. If bipolar diathermy not available use the indifferent electrode pad away from pacing zone , behind the thigh.
Other options.
A .Use a magnet to remove the sensing function of PPM. Application of magnet converts VVI into VOO mode so that external current will not be sensed by the pacemaker and diathermy can be safely used.
B.The other option is use the magnet only if interference problem occur .Magnet should be availableas safety measure.
Dr.S.Venkatesan MD 