Adverse response to cardiac resynchronisation therapy in patients with septal scar on cardiac MRI preventing a septal right ventricular lead position

PURPOSE

Myocardial scar is an adverse factor when considering which patients are likely to respond to cardiac resynchronisation therapy (CRT). We hypothesized that septal scarring on magnetic resonance imaging (MRI) may be associated with a poor outcome from CRT, which may relate to the inability to place the right ventricular (RV) lead in the septum.

METHODS

Fifty patients (ejection fractions, 25 ± 8%; 45 men, 62.8 ± 14 years; 26 dilated cardiomyopathy; and 24 ischaemic cardiomyopathy (ICM)) receiving CRT underwent delayed enhancement cardiac MRI to assess location and burden of myocardial scar. Acute hemodynamic response (AHR) was evaluated at implant with a pressure wire in the left ventricular (LV) cavity. LV remodelling was determined by reduction in LV end-systolic volume at 6 months.

RESULTS

The presence of ICM with septal scar was associated with a poor acute and chronic response to CRT. This was predominantly due to a worse response in patients with septal scar. Patients without septal scar had a better AHR with a 26.7 ± 28.9% rise in LV dP/dt (max) from baseline vs. -2.8 ± 14.5% for patients with septal scar (P = 0.01) with Biventricular (BIV) pacing. A greater proportion remodelled (56% vs. 20% (P = 0.02)). Furthermore, only 33% of patients with septal scar had an RV septal lead compared with 66% with no septal scar (P = 0.03).

CONCLUSIONS

The presence of septal scar was associated with a poor acute and chronic response to CRT. This may relate to the inability to achieve a RV septal lead placement.

Trends, indications and outcomes of cardiac implantable device system extraction: a single UK centre experience over the last decade

BACKGROUND

The rising number of device implantation has seen a parallel in the rising numbers of lead extraction. Herein we have analysed our experience in cardiac device and lead extraction in a single tertiary centre over the last decade.

METHOD

Retrospective analysis of all consecutive patients undergoing lead extractions performed between 2001 and 2010. Procedural success and complications as defined by the Heart Rhythm Society policy.

RESULTS

A total of 745 leads were extracted with a procedural success of 98.9% [382 cases; partial success in 6.9% (26) cases] and failure in 1.1% (4). Major complication rate was 1% (four cases) and minor complication rate was 3.6%. By both univariate and multivariate analysis only duration of lead implantation was an indicator for success (p < 0.0001). The mean implantation time for failed lead extraction was 203 ± 64 months compared with 71.8 ± 16.5 months in the successful cohort (p < 0.0001). Laser-assisted extraction was required in 176 cases. With regard to extraction indication, lead malfunction/recall showed a significant increase during the study period (p = 0.03). On time trend analysis the rise in coronary sinus (CS) lead extraction over time was significant. (p = 0.02) Despite a trend for increased laser use over time this did not achieve statistical significance, p = 0.06.

CONCLUSIONS

A decade's experience of percutaneous lead extraction suggests that a high procedural success rate with a low complication rate is achieved in a high-volume centre. During this time, an increase in both defibrillator and CS lead explantation and a rising trend in laser assistance with almost 50% of cases needing laser usage were observed.

Standardization of fungal polymerase chain reaction for the early diagnosis of invasive fungal infection

BACKGROUND

An early initiation of antifungal therapy in invasive fungal infections (IFIs) is critical in reducing the high mortality rate. Current diagnosis of fungal infection relies on microscopy, culture, antigen, antibody specific tests and histological diagnosis. However, these tests either lack sensitivity or specificity. There is thus the need for a rapid, specific and accurate diagnostic method.

OBJECTIVE

The aim of our study was to establish PCR for the rapid detection of Candida and Aspergillus species in clinical specimens with improved sensitivity and specificity.

MATERIALS AND METHODS

A total of 71 proven cases of IFI (confirmed by culture) were collected. A total of 15 healthy, 15 patients suffering from bacterial sepsis and 15 patients with HIV, HBV viral infections were included as controls. Clinical specimens were subjected to a standardized nested amplification to produce Round I (504 bp) and Round II (150 bp) amplicons. Restriction digestion was performed on these products for further identification.

RESULTS

Analytical sensitivity was determined using 10⁶-10 CFU/ml of cell suspension. The lower detection limit of the assay was 10 CFU/ml of blood. This test was 100% sensitive and specific with a positive predictive value of 100% and a negative predictive value of 96.7%.

CONCLUSION

The assay was found to be effective for the rapid detection of Candida and Aspergillus in clinical specimens.

Multi-site left ventricular pacing as a potential treatment for patients with postero-lateral scar: insights from cardiac magnetic resonance imaging and invasive haemodynamic assessment

AIMS

Multi-site left ventricular (LV) pacing may be superior to single-site stimulation in correcting dyssynchrony and avoiding areas of myocardial scar. We sought to characterize myocardial scar using cardiac magnetic resonance imaging (CMR). We aimed to quantify the acute haemodynamic response to single-site and multi-site LV stimulation and to relate this to the position of the LV leads in relation to myocardial scar.

METHODS

Twenty patients undergoing cardiac resynchronization therapy had implantation of two LV leads. One lead (LV1) was positioned in a postero-lateral vein, the second (LV2) in a separate coronary vein. LV dP/dtmax was recorded using a pressure wire during stimulation at LV1, LV2, and both sites simultaneously (LV1 + 2). Patients were deemed acute responders if ΔLV dP/dtmax was ≥ 10%. Cardiac magnetic resonance imaging was performed to assess dyssynchrony as well as location and burden of scar. Scar anatomy was registered with fluoroscopy to assess LV lead position in relation to scar.

RESULTS

LV dP/dtmax increased from 726 ± 161 mmHg/s in intrinsic rhythm to 912 ± 234 mmHg/s with LV1, 837 ± 188 mmHg/s with LV2, and 932 ± 201 mmHg/s with LV1 and LV2. Nine of 19 (47%) were acute responders with LV1 vs. 6/19 (32%) with LV2. Twelve of 19 (63%) were acute responders with simultaneous LV1 + 2. Two of three patients benefitting with multi-site pacing had the LV1 lead positioned in postero-lateral scar.

CONCLUSION

Multi-site LV pacing increased acute response by 16% vs. single-site pacing. This was particularly beneficial in patients with postero-lateral scar identified on CMR.

Recurrence risk of stillbirth in a second pregnancy

OBJECTIVE

To examine the risk of recurrence of stillbirth in a second pregnancy.

DESIGN

Retrospective cohort study.

SETTING

Scotland, UK.

POPULATION

All women who delivered their first and second pregnancies in Scotland between 1981 and 2005.

METHODS

All women delivering for the first time between 1981 and 2000 were linked to records of their second pregnancy using routinely collected data from the Scottish Morbidity Returns. Women who had an intrauterine death in their first pregnancy formed the exposed cohort, whereas those who had a live birth formed the unexposed cohort.

MAIN OUTCOME MEASURE

Stillbirth in a second pregnancy.

RESULTS

After adjusting for confounding factors, the odds of recurrence of stillbirth in a second pregnancy were found to be 1.94 (99% CI 1.29-2.92) compared with women who had had a live birth in their first pregnancy. Other factors associated with recurrence of stillbirth in a second pregnancy included placental abruption (adjusted OR 1.96; 99% CI 1.60-2.41), preterm delivery (adjusted OR 7.45; 99% CI 5.91-9.39) and low birthweight (adjusted OR 6.69; 99% CI 5.31-8.42). A Bayesian analysis using minimally informative normal priors found the risk of recurrence of stillbirth in a second pregnancy to be 1.59 (99% CI 1.10-2.33).

CONCLUSIONS

Women who have stillbirth in their first pregnancy have a higher risk of recurrence in their next pregnancy.

Non-invasive fetal lung assessment using diffusion-weighted imaging

OBJECTIVES

The main goal was to develop a reproducible method for estimating the diffusion of water in human fetal lung tissue using diffusion-weighted imaging (DWI). A secondary objective was to determine the relationship of the apparent diffusion coefficients (ADCs) in the fetal lung to menstrual age and total lung volume.

METHODS

Normal pregnant volunteers were scanned on a 1.5-Tesla (T) magnetic resonance imaging (MRI) system. The MRI system was equipped with 40-mT/m gradients (slew rate 200 T/m/s, rise time 0.2 ms). A six-channel body array coil was used for signal reception. Single-shot DWI utilized TE/TR 125/3400 ms, slice thickness 4 mm, field of view 280 mm x 280 mm, interslice gap 0.8 mm and a matrix of 128 x 128. The voxel size was 2.5 mm x 2.5 mm x 4.0 mm. Two b-values (0 and 1000) were chosen along three orthogonal directions. ADC maps were created using assigned b-values. Simple linear regression was performed with Pearson correlation coefficient. Interexaminer and intraexaminer bias, and 95% limits of agreement (LOA) were determined using Bland-Altman plots.

RESULTS

Forty-seven scans were performed at a mean +/- SD of 29.2 +/- 4.5 weeks. The median coefficient of variation for ADC was 5.6% (interquartile range, 4.0-8.1%). No differences in ADC values were found between right and left lungs. Normally distributed ADC measurements were not significantly correlated with either total lung volume (r(2) = 0.0001, P = 0.94) or menstrual age (r(2) = 0.003, P = 0.70). The mean ADC value was 1.75 (95% CI, 1.63-1.86). Mean +/- SD intraexaminer bias was -0.15 +/- 2.3 (95% LOA, -4.7 to + 4.4) and interexaminer bias was 2.2 +/- 3.5 (95% LOA, -4.7 to + 9.1).

CONCLUSIONS

Our findings suggest that ADC measurements of the fetal lung are reproducible between blinded examiners and are independent of menstrual age, as well as lung volume.

Hereditary angioedema and pregnancy: successful management of recurrent and frequent attacks of angioedema with C1-inhibitor concentrate, danazol and tranexamic acid - a case report

Hereditary angioedema (HAE) is a rare but potentially life-threatening condition caused by deficiency of C1 esterase inhibitor. It is characterized by subcutaneous swelling in any part of the skin, gastrointestinal and respiratory tracts. We present the case of a pregnant woman with known HAE that deteriorated during pregnancy with frequent attacks that were managed successfully with danazol, tranexamic acid and regular intravenous administration of C1 esterase inhibitor.