Coronary anatomy: Difference between revisions

Coronary anatomy (view source)

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 Figure 2
+[[File:TimeOut_figure2.gif]]
+#Anterobasal
+#Anterolateral
+#Apical
+#Inferior
+#Posterobasal
+#Posterolateral
+#Lateral
+#Septal
 Figure 3
+[[File:TimeOut_figure3.gif]]
+Left ventriculography during systole showing apical ballooning akinesis with basal hyperkinesis in a patient with takotsubo cardiomyopathy.
+=Shock=
+Cardiogenic shock is the inability of the heart, as a result of impairment of its pumping function, to deliver sufficient blood flow to the tissues to meet resting metabolic demands<cite>Califf</cite>. There is poor cardiac output and evidence of tissue hypoxia in the presence of adequate intravascular volume. The diagnosis is indicated by low blood pressure (<90mm Hg, or <30mm Hg below basal levels), a depressed cardiac index (< 2.2 L/min) in the presence of an elevated pulmonary-capillary wedge pressure (> 15 mmHg).
+Causes of cardiogenic shock are:
+*Acute myocardial infarction (left or right)
+*Mechanical complication
+**Acute mitral regurgitation due to papillary muscle dysfunction or rupture
+**Ventricular septal rupture
+**Free-wall rupture
+**Left ventricular aneurysm
+*Other causes
+**Myocarditis
+**Mycoardial contusion
+**Left ventricular outflow tract obstruction (aortic stenosis, hypetrophic obstructive cardiomyopathy)
+**Left ventricular inflow tract obstruction (mitral stenosis, intracardiac tumour)
+**After cardiopulmonary bypass
+=Intra-aortic balloon counterpulsation=
+''Background''
+<br/>
+The intra-aortic balloon pump (IABP) was first introduced in 1968<cite>Kantrowitz</cite>. It uses counterpulsation to increase aortic pressure during diastole and decreasing aortic pressure during systole. This improves the artery blood supply while decreasing the impedance for blood from the ventricle during systole<cite>Baim2</cite>.
+[[File:IntraAortic_figure1.jpg]]
+Figure 1: intra-aortic location of IABP
+[[File:IntraAortic_figure2.jpg]]
+Figure 2: balloon pressure curve.
+''Technique''
+<br/>
+The balloon pump system consists of a balloon-tipped catheter (polyurethane, 10cm, 40ml, dual lumen) that is positioned in the descending aorta 1 to 2 cm beyond the origin of the left subclavian artery and is inserted percuteaneously through a 8-9 French sheath. The balloon is inflated in with helium after aortic valve closure (triggered on the R wave of surface ECG), and maintained until just before the beginning of systolic ejection when the helium is abruptly withdrawn. When appropriately timed, the effect of the IABP is to reduce ventricular afterload and increase cardiac output.
+''Indication''
+<br/>
+Indication for IABP:
+*Cardiogenic shock secondary to myocardial infarction with continuing ischemia, ventricular septal rupture or mitral regurgitation, myocarditis, sepsis (IIb indication in ESC STEMI guideline<cite>EurHeart</cite>)
+*Inability to wean from bypass after cardiac surgery
+*Severe arrhythmia owing to refractory ischemia
+*Prophylactic high risk intervention (high risk PCI due to LV dysfunction or large territory at risk, severe multivessel disease, left main disease)
+Contra-indications are:
+*Significant aortic regurgitation
+*Abdominal aortic aneurysm
+*Aortic dissection
+*High risk of bleeding
+*Bilateral femoral-popliteal bypass grafts
+''Precautions''
+<br/>
+The level of anticoagulation should be monitored daily, with aPTT maintained 50-70 seconds to prevent thrombotic or embolic complications. Evalutions of the limbs and peripheral circulation should be checked regularly. Before removal, patients are weaned by decreasing the counterpulsation (to 1:2/1:3). The incidence of major complications is 2.8%. Common complications are limb ischemia, access site bleeding and balloon leak. Risk factors for complications are female sex, older age (>75 years), BSA < 1.65m2 and peripheral vascular disease.
+''Clinical results''
+<br/>
+In one meta-analyses including 7 randomized trials with STEMI patients with cardiogenic shock, IABP showed neither a 30-day survival benefit nor improved left ventricular ejection fraction, and was associatied with more complications (higher stroke, higher bleeding rates). Another meta-analysis included 9 cohorts with STEMI patients with cardiogenic shock, and showed that IABP was associated with an 18% decrease in 30 day mortality, but with significantly higher revascularization rates and higher mortality in the PCI group<cite>EurHeart2</cite>.  In the randomized controlled trial Shock II, publiced in the NEJM in 2012, the use of IABP did not significantly reduce the 30-day mortality in patients with cardiogenic shock complicating acute myocardial infarction for whom an early revascularization strategy was planned<cite>Thiele</cite>.
 = References =
@@ Line 176: / Line 246: @@
 #Baim Baim DS. Grossman’s cardiac catheterization, angiography, and intervention. 7th edition 2006. Lipincott Williams & Wilkins, Philadelphia PA USA. Chapter 12: 222-233.
 #Hartcatheterisatie https://www.mst.nl/opleidingcardiologie/modules/hartcatheterisatie/
+#Califf pmid=8190135
+#Kantrowitz pmid=5694059
+#Baim2 Baim DS. Grossman’s cardiac catheterization, angiography, and intervention. 7th edition 2006. Lipincott Williams & Wilkins, Philadelphia PA USA. Chapter 21: 412-430.
+#EurHeart pmid=22922416
+#EurHeart2 pmid=19168529
+#Thiele pmid=22920912
 </biblio>