Cardiophile MD » Angiography and Interventions

Nanto’s technique for changing a PTCA balloon catheter over a regular-length guide wire

admin — Mon, 23 Apr 2012 02:19:05 +0000

Nanto’s technique for changing a percutaneous transluminal coronary angioplasty (PTCA) balloon catheter over a regular-length guide wire is demonstrated in this vidoe on youtube: http://www.youtube.com/watch?v=mjEjbSNL4IY (unfortunately the description audio is not in English). This technique is used for changing an over the wire balloon catheter with a regular length of guide wire. But in the 1994 description by Nanto an colleagues available on Pubmed [Nanto S, Ohara T, Shimonagata T, Hori M, Kubori S. A technique for changing a PTCA balloon catheter over a regular-length guidewire. Cathet Cardiovasc Diagn. 1994;32:274-7], they connected the inflation device to the central guide wire lumen of the balloon catheter after pulling back the catheter until the proximal end of the guide wire was just inside. The balloon catheter was further pulled back while applying pressure with the inflation device, leaving the guide wire in the coronary artery. Nanto and colleagues could use this technique successfully in 149 of the 163 procedures attempted. In the youtube video (link above), they seem to have simplified it further by using just a filled luer lock syringe instead of the inflation device.

Risk of acute kidney injury less with higher time interval between angiography and CABG

admin — Mon, 23 Apr 2012 02:18:07 +0000

There is an inverse relation between the time to cardiac surgery after angiography and acute kidney injury. Mehta RH and associates [Relationship of the Time Interval Between Cardiac Catheterization and Elective Coronary Artery Bypass Surgery With Postprocedural Acute Kidney Injury. Circulation. 2011; 124: S149-S155] recently analyzed the data from about two thousand five hundred patients undergoing elective coronary artery bypass surgery (CABG) and confirmed this relationship. The risk of acute kidney injury was highest in those who had CABG within a day of cardiac catheterization, with a mean of twenty four percent vs a mean of about sixteen percent in those who underwent surgery five or more days later. Acute kidney injury was defined as an increase in post CABG serum creatinine of fifty percent or more higher than the baseline value or a new need for dialysis. Post coronary artery bypass grafting acute kidney injury was associated with higher long term risk of death (hazard ratio of 1.268). The authors suggest further studies regarding the utility of delaying elective CABG more than twenty four hours after exposure to contrast agents when feasible with regard to reducing post CABG acute kidney injury.

Ventricular septal defect (VSD)

admin — Mon, 23 Apr 2012 02:02:32 +0000

Swiss cheese ventricular septal defects

Multiple muscular ventricular septal defects (VSD) are also called ‘swiss cheese’ VSD. Swiss cheese VSDs are difficult to close surgically. It is difficult to locate the openings of the VSD from the right ventricular side. Some may have multiple right ventricular openings for a single left ventricular orifice. When one right ventricular orifice is closed, the VSD may be seen puffing from another orifice. These VSDs require left ventriculotomy for closure which is a problem in a small infant. Due to the difficulty fo surgical closure, often a pulmonary artery banding is all that is done in these cases, to control the excessive pulmonary blood flow and development of pulmonary arterial hypertension. Swiss cheese VSDs are associated with left axis deviation on ECG.

Katz-Wachtel phenomenon / sign on ECG in ventricular septal defect

Katz-Wachtel sign / phenomenon

Click on the image for an enlarged view

The Katz-Wachtel sign is tall diphasic RS complexes at least 50 mm in height in lead V2, V3 or V4 – mid precordial leads [Circulation 1963;27;1118-1127 (Free full text at: http://circ.ahajournals.org/cgi/reprint/27/6/1118.pdf); original description by Katz and Wachtel was published in 1937: Katz LN and Wachtel H. The diphasic QRS type of electrocardiogram in congenital heart disease. Am Heart J; 1937, 13: 202-206]. The sign has been described in ventricular septal defect with biventricular hypertrophy in children. It can be seen with isolated ventricular septal defect as well as complex ventricular septal defect. In fact the Circulation article cited is on Complete Transposition of the Great Vessels: II. An Electrocardiographic Analysis by Larry P et al.

Ventricular septal defect – perimembranous

Perimembraneous ventricular septal defect (VSD)

Medium sized ventricular septal defect in peri-membranous location seen from the apical five chamber view. RV: right ventricle; LV: left ventricle; VSD: ventricular septal defect; Ao: aorta; RA: right atrium; LA: left atrium; IVS: interventricular septum. There is aneurysm of the inteverventricular septum covering the VSD, leaving a small gap. The VSD jet passes through this small defect which is restrictive (below).

VSD Jet on continuous wave Doppler

VSD jet documented by continuous wave Doppler interrogation, showing an interventricular gradient of 61.5 mm Hg, which suggests that the defect is restrictive. Actual gradient may be even more as this jet has an incomplete envelope.

Echocardiographic profile in ventricular septal defect

Ventricular septal defect (subaortic) seen from parasternal long axis view

Parasternal long axis view showing aorta (Ao), left atrium (LA), left ventricle (LV) and a small perimembranous (subaortic) ventricular septal defect. Mitral valve is in the open position and the aortic valve in the closed position.

VSD Jet visualised by colour flow mapping (colour Doppler)

Colour sector in parasternal long axis view shows the mosaic (multi-coloured) VSD jet across the perimembranous VSD from the left ventricle to the right ventricle. It is a high velocity jet because the VSD is restrictive. The neck of the jet almost corresponds to the size of the VSD. VSD jet is seen in a systolic frame.

Continuous wave Doppler interrogation of VSD jet

VSD jet can be picked up in parasternal long axis or short axis view, guided by color Doppler. It may also be picked up from the apical four chamber view, but the allignment may not be good. Pulsed Doppler cannot measure the jet velocity as it is much higher than the Nyquist limit of the pulsed Doppler system. Hence continuous wave Doppler is used for interrogation of the VSD jet. The interventricular gradient is calculated using the Bernoulli equation. A high interventricular gradient indicates that the VSD is restrictive. A low gradient indicates unrestrictive VSD and pulmonary hypertension.

Colour Doppler echocardiogram video in perimembranous ventricular septal defect.

Ventricular septal defect and aortic regurgitation

Aortic regurgitation is more likely to occur in subpulmonic ventricular septal defect (VSD) than perimembranous VSD. Aortic cuspal prolapse occurs in 4 – 9% of VSDs and aortic regurgitation in 2 – 6% of VSDs. But the prevalene of aortic cusp prolapse in subpulmonic VSDs is upto 73% and the occurrence of aortic regurgitation about 52 to 78%. While 62% of those with aortic cusp prolapse along with subaoric VSD have aortic regurgitation, 77% to 90% of those with subaoric VSD and aortic regurgitation have aortic cusp prolapse. A study by Saleeb SF et al (Am J Cardiol. 2007;99:1588-92) evaluated 100 patients with subaortic VSD diagnosed in the first year of life, but did not need surgery in infancy were evaluated for the development of aortic regurgitation on follow up. The follow up period ranged from one to twenty four years with a mean of about seven years. Initial VSD size was small in 38 patients, moderate in 50 patients and large in 12 patients. Spontaneous closure of VSD occurred during the follow up period in 4 patients with at a mean age of 6 years with a range of 3.4 to 12.7 years. Three of them had small VSDs and one of them had a moderate sized VSD. Aortic cusp prolapse developed in 14 patients at a mean age of 7.1 years with a range of 0.4 to 18.4 years. The murmur of aortic regurgitation was audible in six patients at mean age of 5.1 ± 3.1 years. All of them had aortic cusp prolapse and underwent surgery with VSD closure and aortic valvuloplasty.

LV – RA shunt: echocardiographic video

A shunt from the left ventricle to the right atrium can occur in three ways: (1) Defect in the atrioventricular septum between the septal attachments of the mitral and tricuspid valves (2) A perimembraneous ventricular septal defect (VSD) with associated fenestration of the septal tricuspid leaflet so that the VSD jet is partly directed from the left ventricle across the interventricular septum through the tricuspid valve into the right atrium (3) Ventricular septal defect with tricuspid regurgitation so that the blood shunted from the left ventricle is passed immediately to the right atrium to produce a step up in oximetry.

A defect in the atrioventricular septum was described by Gerbode F et al in 5 operated cases in 1958 [Gerbode F., Hultgren H., Melrose D., Osborn J. Syndrome of left ventricular-right atrial shunt: successful surgical repair of defect in five cases, with observation of bradycardia on closure. Ann Surg 1958;148(3):433-446]. Anatomically this defect is possible because the septal attachment of the tricuspid valve is distal to that of the mitral valve so that there is a small region of the septum which is between the left ventricle and the right atrium, known as the atrioventricular septum. Usually the defect is congenital. But cases are on record in which the septal defect was acquired due to infective endocarditis. It is mentioned that congenital variety of defect occurs inferior to the tricuspid valve while the aquired variety is superior to the valve.

LV – RA shunt in perimembranous VSD across STL fenestration

The still image shows both the jet from the left ventricle to the right ventricle across the perimembranous VSD and the jet from left ventricle to right atrium across the VSD, through the fenestration in the septal tricuspid leaflet into the right atrium.

Echocardiographic video (color Doppler) showing LV – RA shunt through VSD, across the STL

Initial view shows the mosaic jet from left ventricle to right ventricle across the subaortic VSD as well as another jet traversing the defect in the septal tricuspid leaflet into the right atrium. This second jet resembles a tricuspid regurgitation jet. Second view is the parasternal short axis view of flow from the left ventricule to right ventricle, in the classical location of a perimembranous VSD.

During echocardiographic evaluation, the jet of the Gerbode VSD is likely to be mistaken as a tricuspid regurgitation jet. This will cause misinterpretation as severe pulmonary hypertension while in fact the right ventricular pressures may be low. This can be identified by carefully visualizing the jet origin on colour Doppler. The structural defect can also be seen by careful two dimensional imaging. Pulmonary arterial pressure can be counter checked by using the pulmonary regurgitation jet.

Hepatoclavicular view for left ventriculography

LAO (left anterior oblique) 40 degrees with 40 degrees cranial angulation is known as hepatoclavicular view. It is used to profile inlet ventricular septal defects. Sub pulmonic VSDs may be seen only in RAO (right anterior oblique) views.

Chronic total occulusion (CTO) an independent predictor of ventricular arrhythmias

admin — Mon, 23 Apr 2012 01:52:06 +0000

Chronic total occulusion (CTO) has been identified as an independent predictor of ventricular arrhythmias in the VACTO Primary Study [Nombela-Franco L et al. Ventricular Arrhythmias Among Implantable Cardioverter Defibrillator Recipients for Primary Prevention: Impact of Chronic Total Coronary Occlusion (VACTO Primary Study). CIRCEP.111.968008 Published online before print December 28, 2011,
doi: 10.1161/?CIRCEP.111.968008]. They included all consecutive patients receiving implantable cardioverter defibrillators (ICD) for coronary artery disease and identified seventy one patients out of a total of one hundred and sixty two patients as having at least one chronic total occlusion. The presence of CTO was associated with higher rates of ventricular arrhythmia requiring ICD therapy and higher mortality with a log-rank <0.01. Chronic total occlusion was also independently associated with appropriate ICD intervention on multivariate analysis with a hazard ratio of 3.5 (p=0.003).

Late and very late stent thrombosis with drug eluting stents

admin — Mon, 23 Apr 2012 01:49:35 +0000

Late and very late stent thrombosis with drug eluting stents still continue to be our concern. Fresh data from the jCypher registry is available from Kimura T and associates [Very Late Stent Thrombosis and Late Target Lesion Revascularization after Sirolimus-Eluting Stent Implantation: Five-year Outcome of the j-Cypher Registry. CIRCULATIONAHA.111.046599. Published online before print December 27, 2011, doi: 10.1161/?CIRCULATIONAHA.111.046599]. In this group of over twelve thousand and eight hundred patients undergoing sirolimus eluting stent implanation, the one month stent thrombosis was 0.3% while the one year cumulative stent thrombosis rate was 0.6%. Five year cumulative stent thrombosis rate was 1.6%. Acute coronary syndrome and proximal left anterior descending coronary artery were risk factors for early stent thrombosis. Side branch stenting, diabetes mellitus and end stage renal disease with or without hemodialysis were risk factors for late stent thrombosis. Current smoking and total stent length more than twenty eight millimeters were risk factors for very late stent thrombosis. Early stent thrombosis was calculated at thirty days, late stent thrombosis at one year and very late stent thrombosis at five years. Late and very late stent thrombosis rates were calculated at 0.26% per year. Target vessel revascularization (TLR) within first year was low at 7.35%. Beyond one year, it continued at a rate of 2.2% per year upto five years.

T-stenting and small protrusion (TAP stenting) in coronary bifurcations

admin — Mon, 23 Apr 2012 01:48:54 +0000

T-stenting and small protrusion technique (TAP-Stenting) is used to enhance side branch ostial coverage. It is an intentional protrusion of side branch stent within the main branch during coronary bifurcation stenting which ensures side branch ostial coverage and facilitates final kissing balloon inflation [Burzotta et al Catheterization and Cardiovascular Interventions. 2007; 70:75–82]. This technique has been introduced because the conventional T-stenting method is associated with the risk of incomplete side branch ostial coverage, especially when the angle between the main branch and the side branch is acute. The position of the side branch stent is
adjusted to fully cover the proximal (or upper) part of the side branch ostium. This causes a small protrusion of side branch stent in the lower part of the ostium. This is leveled off by the final kissing inflation.

Lutembacher syndrome: combination of atrial septal defect with mitral stenosis

admin — Mon, 23 Apr 2012 01:46:59 +0000

The original description of Lutembacher syndrome was as a combination of atrial septal defect with mitral stenosis [Lutembacher R. De la sténose mitrale avec communication interauriculaire. Archives des maladies du coeur et des vaisseaux, Paris, 1916, 9: 237-260]. Though Lutembacher thought that both atrial septal defect and mitral stenosis were congenital, it is likely that in that sixty one year old lady, the atrial septal defect was congenital and mitral stenosis of rheumatic etiology. Later on several authors called a combination of atrial septal defect with any mitral valve lesion (stenosis, regurgitation or a combination) as Lutembacher syndrome. Some expanded it to include any left to right shunt at the atrial level. Recently even atrial level shunts created by septal puncture for balloon mitral valvotomy has been included in the spectrum of Lutembacher syndrome. Personally I would prefer to restrict the terminology to a combination of congenital atrial septal defect and rheumatic mitral stenosis as would have been the etiology of the original Lutembacher’s case. Presence of the two lesions have significant hemodynamic effects on the other lesion. The large unrestrictive atrial septal defect lowers the left atrial pressure and gradient across the mitral valve so that findings of mitral stenosis may be obscured and so will be the features of pulmonary venous congestion. In the presence of a large atrial septal defect, even a small gradient across the mitral valve is to be taken as significant. The obstruction to the left ventricular inflow on the other hand enhances the left to right shunt across interatrial septum so that torrential left to right shunts are likely in Lutembacher syndrome. This manifests as prominent right ventricular outflow murmur with a thrill. Cardiomegaly is also common. George Joseph and associates from Christian Medical College Hospital, Vellore, India has described complete percutaneous management of Lutembacher syndrome [Definitive percutaneous treatment of Lutembacher's syndrome. Catheter Cardiovasc Interv. 1999;48:199-204]. They closed the atrial septal defect with an Amplatzer septal occluder and dilated the stenotic mitral valve with Joseph balloon mitral valvotomy catheter (JOMIVA balloon).

Lower very late stent thrombosis with everolimus eluting stents (EES)

admin — Mon, 23 Apr 2012 01:45:39 +0000

Though drug eluting stents have a much lower incidence of restenosis after percutaneous coronary intervention, late stent thrombosis and very late stent thrombosis occurring beyond one year after stent implantation are of great concern. This is especially when the individual needs withdrawal of dual antiplatelet therapy for a surgical procedure. A recent study by Raber L and colleagues have given some relief in that everolimus eluting stents have been shown superior to serolimus eluting stents and paclitaxel eluting stent [Very Late Coronary Stent Thrombosis of a Newer-Generation Everolimus-Eluting Stent Compared With Early-Generation Drug-Eluting Stents. A Prospective Cohort Study. Circulation. 2012; 125: 1110-1121]. They evaluated a cohort of over twelve thousand patients with unrestricted use of drug eluting stents of which over three thousand and eight hundred had serolimus eluting stents, over four thousand three hundred had paclitaxel eluting stents and over four thousand and two hundred had everolimus eluting stents implanted. The overal rate of thrombosis over the follow which ranged up to four years was 1.4 per hundred person-years for everolimus eluting stents. The figure was 2.9 for serolimus eluting stents and 4.4 for paclitaxel eluting stents (p<0.0001). The rates of early and late stent thrombosis were also similarly lower. There was also a lower risk of death or myocardial infarction with everolimus eluting stents when compared to paclitaxel eluting stents (p<0.0001) which was directly related to the stent thrombosis associated events.

Coronary angiography prior to surgery for valvular heart disease

admin — Mon, 23 Apr 2012 01:41:09 +0000

Coronary angiography prior to surgery for valvular heart disease is considered for those forty years and above if there are no coronary risk factors and for those thirty five years and above when there are coronary risk factors.

FFR to assess need for a side branch stent

admin — Mon, 23 Apr 2012 01:40:37 +0000

Fractional flow reserve (FFR) estimation using the Doppler wire is useful in assessing the need for a side branch stent in bifurcation disease. Usually a stent is considered in bifurcation disease only if the side branch is large and almost equal in size to the distal vessel. Using a side branch stent increases the risk of stent thrombosis in the main vessel and is especially to be avoided in a thrombotic situation as in acute myocardial infarction. If an FFR is available, it can measure the pressure difference across the lesion and if the distal pressure is more than 0.75 times the proximal pressure (FFR >0.75) a side branch stent is considered unnecessary.