Limits...
Cardiac sympathetic activity in chronic heart failure: cardiac 123 I- m IBG scintigraphy to improve patient selection for ICD implantation

View Article: PubMed Central - PubMed

ABSTRACT

Heart failure is a life-threatening disease with a growing incidence in the Netherlands. This growing incidence is related to increased life expectancy, improvement of survival after myocardial infarction and better treatment options for heart failure. As a consequence, the costs related to heart failure care will increase. Despite huge improvements in treatment, the prognosis remains unfavourable with high one-year mortality rates. The introduction of implantable devices such as implantable cardioverter defibrillators (ICD) and cardiac resynchronisation therapy (CRT) has improved the overall survival of patients with chronic heart failure. However, after ICD implantation for primary prevention in heart failure a high percentage of patients never have appropriate ICD discharges. In addition 25–50 % of CRT patients have no therapeutic effect. Moreover, both ICDs and CRTs are associated with malfunction and complications (e. g. inappropriate shocks, infection). Last but not least is the relatively high cost of these devices. Therefore, it is essential, not only from a clinical but also from a socioeconomic point of view, to optimise the current selection criteria for ICD and CRT. This review focusses on the role of cardiac sympathetic hyperactivity in optimising ICD selection criteria. Cardiac sympathetic hyperactivity is related to fatal arrhythmias and can be non-invasively assessed with 123I-meta-iodobenzylguanide (123I-mIBG) scintigraphy. We conclude that cardiac sympathetic activity assessed with 123I-mIBG scintigraphy is a promising tool to better identify patients who will benefit from ICD implantation.

No MeSH data available.


Related in: MedlinePlus

Two examples of planar cardiac 123I-mIBG scintigraphy using a medium collimator with different late (4h p.i.) myocardial 123I-mIBG uptake in subjects with the same LVEF compared with a healthy subject. a 63-year-old patient with ischaemic heart failure. b 68-year-old patient with ischaemic heart failure. c 32-year-old healthy person. d Example of placing a region-of-interest (ROI) over the heart (H) and fixed rectangular mediastinal ROI placed on the upper part of the mediastinum (M) for calculating H/M ratio
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120011&req=5

Fig3: Two examples of planar cardiac 123I-mIBG scintigraphy using a medium collimator with different late (4h p.i.) myocardial 123I-mIBG uptake in subjects with the same LVEF compared with a healthy subject. a 63-year-old patient with ischaemic heart failure. b 68-year-old patient with ischaemic heart failure. c 32-year-old healthy person. d Example of placing a region-of-interest (ROI) over the heart (H) and fixed rectangular mediastinal ROI placed on the upper part of the mediastinum (M) for calculating H/M ratio

Mentions: To block uptake of free 123I by the thyroid gland, subjects are pretreated with 250 mg of oral potassium iodide 30 min before intravenous injection of 185 MBq 123I-mIBG. Fifteen minutes (early acquisition) and 4 h (late acquisition) after administration of 123I-mIBG, 10-min planar images are acquired with the subjects in a supine position using a gamma camera equipped with a low energy high resolution or medium collimator. Based on the obtained planar (2D) images, three major outcomes of myocardial 123I-mIBG uptake can be determined: the early and late heart/mediastinal (H/M) ratio and cardiac washout rate (WO). The H/M ratio is calculated from planar 123I-mIBG images using a regions-of-interest (ROI) over the heart (Fig. 3). Standardised background correction is derived from a fixed rectangular mediastinal ROI placed on the upper part of the mediastinum [32]. The location of the mediastinal ROI is determined in relation to the lung apex, the lower boundary of the upper mediastinum, and the midline between the lungs. The H/M ratio is calculated by dividing the mean count density in the cardiac ROI by the mean count density in the mediastinal ROI [32]. The 123I-mIBG WO can be calculated using early and late H/M ratio (1). There are variations to the WO calculation using the myocardial count densities only, requiring a time-decay correction (factor of 1.21), without (2) or with background correction (3):Fig. 3


Cardiac sympathetic activity in chronic heart failure: cardiac 123 I- m IBG scintigraphy to improve patient selection for ICD implantation
Two examples of planar cardiac 123I-mIBG scintigraphy using a medium collimator with different late (4h p.i.) myocardial 123I-mIBG uptake in subjects with the same LVEF compared with a healthy subject. a 63-year-old patient with ischaemic heart failure. b 68-year-old patient with ischaemic heart failure. c 32-year-old healthy person. d Example of placing a region-of-interest (ROI) over the heart (H) and fixed rectangular mediastinal ROI placed on the upper part of the mediastinum (M) for calculating H/M ratio
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120011&req=5

Fig3: Two examples of planar cardiac 123I-mIBG scintigraphy using a medium collimator with different late (4h p.i.) myocardial 123I-mIBG uptake in subjects with the same LVEF compared with a healthy subject. a 63-year-old patient with ischaemic heart failure. b 68-year-old patient with ischaemic heart failure. c 32-year-old healthy person. d Example of placing a region-of-interest (ROI) over the heart (H) and fixed rectangular mediastinal ROI placed on the upper part of the mediastinum (M) for calculating H/M ratio
Mentions: To block uptake of free 123I by the thyroid gland, subjects are pretreated with 250 mg of oral potassium iodide 30 min before intravenous injection of 185 MBq 123I-mIBG. Fifteen minutes (early acquisition) and 4 h (late acquisition) after administration of 123I-mIBG, 10-min planar images are acquired with the subjects in a supine position using a gamma camera equipped with a low energy high resolution or medium collimator. Based on the obtained planar (2D) images, three major outcomes of myocardial 123I-mIBG uptake can be determined: the early and late heart/mediastinal (H/M) ratio and cardiac washout rate (WO). The H/M ratio is calculated from planar 123I-mIBG images using a regions-of-interest (ROI) over the heart (Fig. 3). Standardised background correction is derived from a fixed rectangular mediastinal ROI placed on the upper part of the mediastinum [32]. The location of the mediastinal ROI is determined in relation to the lung apex, the lower boundary of the upper mediastinum, and the midline between the lungs. The H/M ratio is calculated by dividing the mean count density in the cardiac ROI by the mean count density in the mediastinal ROI [32]. The 123I-mIBG WO can be calculated using early and late H/M ratio (1). There are variations to the WO calculation using the myocardial count densities only, requiring a time-decay correction (factor of 1.21), without (2) or with background correction (3):Fig. 3

View Article: PubMed Central - PubMed

ABSTRACT

Heart failure is a life-threatening disease with a growing incidence in the Netherlands. This growing incidence is related to increased life expectancy, improvement of survival after myocardial infarction and better treatment options for heart failure. As a consequence, the costs related to heart failure care will increase. Despite huge improvements in treatment, the prognosis remains unfavourable with high one-year mortality rates. The introduction of implantable devices such as implantable cardioverter defibrillators (ICD) and cardiac resynchronisation therapy (CRT) has improved the overall survival of patients with chronic heart failure. However, after ICD implantation for primary prevention in heart failure a high percentage of patients never have appropriate ICD discharges. In addition 25–50 % of CRT patients have no therapeutic effect. Moreover, both ICDs and CRTs are associated with malfunction and complications (e. g. inappropriate shocks, infection). Last but not least is the relatively high cost of these devices. Therefore, it is essential, not only from a clinical but also from a socioeconomic point of view, to optimise the current selection criteria for ICD and CRT. This review focusses on the role of cardiac sympathetic hyperactivity in optimising ICD selection criteria. Cardiac sympathetic hyperactivity is related to fatal arrhythmias and can be non-invasively assessed with 123I-meta-iodobenzylguanide (123I-mIBG) scintigraphy. We conclude that cardiac sympathetic activity assessed with 123I-mIBG scintigraphy is a promising tool to better identify patients who will benefit from ICD implantation.

No MeSH data available.


Related in: MedlinePlus