Cardiac magnetic resonance in the assessment of pericardial abnormalities: a case series

Background

Cardiac magnetic resonance (CMR) has a unique role in evaluating pericardial disease, permitting non-invasive tissue analysis, and haemodynamic assessment.

Case summary

In Case 1 of recurrent pericarditis, CMR confirmed reactivation of inflammation with late gadolinium enhancement and native T1/T2 mapping techniques, prompting therapeutic changes. In constrictive pericarditis, CMR is the only modality capable of differentiating a subacute potentially reversible form (Case 2), from a chronic, burnt out irreversible phase characterized by constrictive physiology (Case 3).

Discussion

Cardiac magnetic resonance is an effective tool to tailor individual therapy, particularly in cases of recurrent and constrictive pericarditis. Late gadolinium enhancement provides diagnostic and prognostic information, and multiparametric mapping has emerged as a promising tool with incremental diagnostic value.

Coronary microvascular dysfunction in hypertrophic cardiomyopathy – impact from tissue characteristics to clinical manifestations

Background

Coronary microvascular dysfunction (CMD) is an important pathophysiological feature in hypertrophic cardiomyopathy (HCM).

Purpose

This study investigated the role of CMD in tissue characteristics, left ventricular (LV) systolic performance and clinical manifestations in HCM.

Methods

This prospective study enrolled patients with HCM without obstructive epicardial coronary artery disease. Each patient underwent cardiovascular magnetic resonance (CMR) including parametric mapping, perfusion imaging during regadenoson-induced hyperemia, late gadolinium enhancement (LGE) and three-dimensional longitudinal, circumferential and radial strains analysis. Electrocardiogram and 24 hours Holter recording were performed to assess arrhythmias.

Results

75P were enrolled, 47 (63%) males, mean age 54.6 (14.8) years; 51 patients (68%) had non obstructive HCM, mean maximum wall thickness (MWT) was 20.2 (4.6)mm, LV ejection fraction 71.6 (8.3)%, ischemic burden 22.5 (16.9)% of LV.

Greater MWT was associated the severity of ischemia (β-estimate: 1.809, 95% CI: 1.073; 2.545; p<0.001).

Ischemic burden was strongly associated with higher values of native T1 (β-estimate: 9.018, 95% CI: 4.721, 13.315; p<0.001).

An association between ischemia and the extent of LGE was found (β-estimate: 2.02, 95% CI: 0.93, 3.10; p<0.001). Ischemia in ≥21% of LV was associated with LGE >15% (AUC 0.766, sensitivity 0.724, specificity 0.659).

In multivariable analysis, in the overall population, MWT and LGE were independently associated with ischemia, however the evidence of association between ischemia and extent of LGE became weaker (β-estimate: 1.070, 95% CI: −0.106; 2.245; p=0.074).

In subgroup analysis, the association between ischemia and LGE remained significant in individuals with MWT 15–20mm, non-obstructive HCM, female and age <40 years.

The severity of ischemia was not associated with markers of LV systolic function, namely LVEF, longitudinal, radial and circumferential strain

A strong evidence of association was found between ischemia and atrial fibrillation/flutter (AF/AFL) (OR: 1.481, 95% CI: 1.020,2.152; p=0.039), but no association was verified with non-sustained ventricular tachycardia.

Conclusion

In HCM, CMD is related to the severity of LV hypertrophy. Ischemia secondary to CMD promotes fibrosis and is associated with an increase in the odds of AF/ALF.

Funding Acknowledgement

Type of funding sources: None.

Upright exercise stress echocardiography may unmask dynamic left ventricular obstruction also beyond hypertrophic cardiomyopathy

Background

Dynamic left ventricular outflow obstruction (LVOTO) during exercise stress echocardiography (ESE) is recommended in hypertrophic cardiomyopathy (HCM) to identify the obstructive phenotype.

Aim

To assess left ventricular outflow gradient (LVOTG) during ESE in different conditions.

Methods

In a single-group, prospective, observational study, we performed peak and/or post-treadmill ESE with systematic assessment of LVOTG in the orthostatic position by continuous-wave Doppler in 1333 subjects (837 males, mean age 38,2±20 ranging from 6 to 87 years) recruited over a period of twenty years, from 2001 to 2021. Peak LVOTG ≥30 mm Hg was considered abnormal for LVOTO during ESE. We enrolled 7 different populations: asymptomatic healthy controls (n=35); HCM (n=81); genotype-positive, phenotype negative asymptomatic HCM (n=6); patients with chest pain symptoms, suspected myocardial ischemia and either normal coronary arteries (INOCA, n=131,or with very low pre-test probability of coronary artery disease (probable INOCA, n=416) and; fatigue and suspected heart failure with preserved ejection fraction (HFpEF, n=206); amateur athletes with ischemia-like ECG changes during exercise-test or symptoms such as near syncope or chest pain or dizziness (n=457); aborted sudden death and with negative screening (n=1).

Results

Technical success rate of LVOTG assessment was 1333/1333 at rest and at peak stress (feasibility 100%). Imaging and analysis time were <1 minute. LVOTG at rest was present in 25 pts (2.8%) of the overall population: 23 HCM, 1 INOCA, and 1 HFpEF. Overall prevalence during ESE was 432/1333 (32%). During ESE, LVOTO (see Figure 1 and 2) was 0% (0/35) in normals, 58% (47/81) in HCM (23 with obstruction at rest), 33% (2/6) in genotype-positive, phenotype negative HCM, 37% (33/131) in INOCA, 40% (135/416) in athletes and 1/1 in the patient with aborted sudden death on strenuous exercise.

Conclusion

LVOTO in orthostatic position is detectable during treadmill ESE in several cardiovascular conditions associated with symptoms such as dyspnea, chest pain or near syncope, and even in asymptomatic patients with genotype-positive, phenotype-negative HCM. The identification of the obstructive phenotype is easy to capture during ESE without any significant additional imaging and analysis burden and can be important also outside HCM.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Association between microvascular dysfunction and impaired myocardial deformation in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Objective

To analyze the relationship between coronary microvascular dysfunction (MCD) and left ventricular (LV) myocardial deformation in hypertrophic cardiomyopathy (HCM). 

Methods

Prospectively inclusion of HCM patients (P). MCD was assessed by CMR, during regadenoson-induced hyperemia. For perfusion assessment, the myocardium was divided into 32 subsegments (16 AHA segments subdivided into an endocardial and epicardial layer). Ischemic burden was calculated as the number of involved subsegments, assigning 3% of myocardium to each subsegment. Epicardial coronary artery disease was excluded by computed tomography or invasive coronary angiography.

LV myocardial deformation was evaluated by 2D and 3D speckle-tracking echocardiography (STE), including global longitudinal strain (GLS), peak systolic dispersion (PDS), global circumferential strain (GCS), global radial strain (GRS), area strain, twist and torsion.

Results

31 P enrolled (51%male,age57.8 ± 15.5years). Asymmetric septal hypertrophy was seen in 55%, apical in 29%, concentric in 16%,maximal wall thickness (MWT) of 20.5 ± 4.9mm; 26% with LVOT obstruction; LV ejection fraction 67.9 ± 7.9%.

In 2DSTE analysis, P with more ischemia (>20%of LV) presented more severe impaired GLS and greater PDS, comparing with patients with ≤20% of ischemia.

Similarly, 3DSTE imaging showed worse LV performance in P with greater ischemic burden, expressed by significant difference in GLS, GRS and area strain. GCS also trended to be worse in the presence of >20% of ischemia.

The stronger correlation was found between 2D GLS and ischemic burden (Pearson correlation factor 0.545; p = 0.002).

Conclusion

In HCM, the severity of ischemia secondary to MCD was associated with impairment in LV myocardial deformation evaluated by 2D and 3D STE.

Table 1. Echocardiography Ischemic burden (% of LV) 2D parameters ≤ 20% (n = 15) > 20% (n = 16) p-value GLS (%) -15.6 ± 2.7 -12.1 ± 4.7 0.016 PSD (ms) 73.2 ± 25.6 102.1 ± 57.6 0.150 3D parameters GLS (%) -10.3 ± 4.5 -7.3 ± 3.0 0.010 GCS (%) -12.6 ± 3.0 -10.1 ± 4.5 0.079 GRS (%) 30.8 ± 8.5 22.8 ± 11.4 0.035 Area strain(%) -20.8 ± 4.9 -15.8 ± 6.3 0.020 Twist (deg) 6.0 ± 4.8 4.1 ± 4.0 0.175 Torsion (deg/cm) 1.2 ± 0.9 0.8 ± 0.7 0.232

Myocardial work: a new way to predict fibrosis in patients with hypertrophic cardiomyopathy

Aims

Late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) adds prognostic information in patients with hypertrophic cardiomyopathy (HCM). Whether Myocardial work (MW), a new parameter on transthoracic echocardiographic (TTE), can predict significant fibrosis in HCM patients is unknown.

Methods

Single-centre evaluation of consecutively recruited HCM patients in which TTE and CMR were performed. MW and related indices were calculated from global longitudinal strain (GLS) and from estimated left ventricular pressure curves. The extent of LGE was quantitatively assessed. LGE ≥15% was chosen to define significant fibrosis.

Logistic regression analysis was used to find the variables associated with LGE ≥15% and cut-off values were determined.

Results

Among the thirty-two patients analysed mean age was 57±16 years, 18 (56%) were male patients and the mean left ventricular ejection fraction by TTE was 67±8%.

Global constructive work (GCW), global work index and GLS were significant predictors of LGE ≥15%. A cut-off ≤1550 mmHg% of GCW was able to predict significant fibrosis with a sensitivity of 92% and a specificity of 79%, while the best cut-off for GLS (>−15%) had a sensitivity of 86% and a specificity of 72%.

Conclusion

GCW was the best parameter to predict significant left ventricular myocardial fibrosis in CMR, suggesting its utility in patients who may not be able to have a CMR study.

Myocardial Work and LGE in CMR in HCM

Funding Acknowledgement

Type of funding source: None

P859 Can we connect intraventricular exercise induced gradients to sudden cardiac death?

Background

Some publications, on exercise induced intraventricular gradients, admit the possibility they can be related to some cases of unexplained sudden cardiac death (SCD).

Clinical case

We present the case of a young male athlete (16 years) that after winning a triathlon competition has sudden cardiac death.

No cardiovascular risk factors.

No family history of SCD

A previous episode of dizziness, accompanied by nausea and vomiting related to intense training happens 6 months before.

In September 2018 about 30 minutes after winning a triathlon competition has SCD episode having been resuscitated on site by the competition physician having been defibrillated and transported to intensive care unit.

After discharge, cardiac MRI, Coronary AngioTC, complete genetic study for heart diseases, flecainid test, transthoracic echocardiogram, stress echocardiogram with hyperventilation and ergometrine. All have normal results (Figure)

During 24 hours Holter ECG isolated premature ventricular complexes were detected and during exercise stress echocardiography a significant intraventricular gradient without systolic anterior movement of mitral valve was detected (Figure).

The athlete was disqualified for sports practice, refuses CDI implantation and started bisoprolol 2,5 mg daily.

To the best of our knowledge this is the first case of association between SCD and exercise induced intraventricular gradient. This possible association should be studied in the future.

Abstract P859 Figure. Intraventricular gradient in SCD athlete

P794 Treadmill exercise stress echocardiography in children; our experience

Background

Exercise stress echocardiography (ESE) is routinely used in adults but its role in children (C) is less established

Purpose

To assess the feasibility and clinical value of ESE in outpatient children

Methods

We enrolled 309 consecutive C (mean age = 14,1 ± 2,6 years, range 6-17 yrs) who underwent treadmill ESE between 2002 and 2019: One group (Group I) of 258 C including: 237 with exercise related symptoms (chest pain and/or dyspnea and/ or lypotimia-syncope), 15 with resting ECG alterations, 6 with positive ECG stress test and other group of C (Group II) including: 10 asymptomatic for screening requested by parents, 11 with symptoms unrelated to exercise, 12 with antecedents of sudden death in the family, and 17 with known pathology - 10 with hypertrophic cardiomyopathy, 2 with aortic coarctation, 1 each with Cortriatriatum sinister, pulmonary stenosis, subaortic stenosis, bicuspid aortic valve, left ventricular hypertrophy related to arterial hypertension, aortic switch operation. Regional wall motion abnormalities (RWMA) by 2-D and continuous wave Doppler (transvalvular or transaortic or intraventricular (IVG) gradients were assessed in all.

Results

The success rate was 309/309 (100%). Only one complication (allowing asthma diagnosis by serendipity) occurred: a severe asthmatic crisis in one girl studied because of chest pain with exercise (with ESE negativity), Stress-induced RWMA occurred in 2 pts (one with HCM, the other with normal coronary arteries). A significant orthostatic exercise induced IVG (> 30 mmHg) was present in 101 of the 258 C (39%) studied due to symptoms, ECG alterations or positive stress ECG.

In group II the C with induced IVG attained

greater heart rate (HR) 184 ± 12 vs 174 ± 16 (p < 0,001); greater blood pressure (BP) 150 ± 19 mmHg vs 136 ± 23 mmHg (p < 0,001). The OR to the reproduced symptoms that motivated the exam during the SE comparing the 101 C with IVG with the 158 without IVG was 8,22 (4,83-13,99) p < 0,001 (95% CI).

Conclusions

Treadmill ESE is feasible and safe in young people. RWMA are of limited usefulness in our outpatient C group. Doppler often documents significant exercise induced IVG, occult at rest that associate with symptoms.

Abstract P794 Figure. ESE Induced IVG in a C with chest pain

P945 Should children, with exercise induced intra-ventricular gradients, be treated with beta blockers?

Background

In our experience, treadmill exercise echocardiography (SE) is feasible and safe in children (C). Regional wall motion abnormalities (RWMA) are of limited usefulness, but Doppler often - (in 39% from 258 previously studied C) - documents significant intraventricular gradients (IVG), occult at rest, and allowing to document a possible explanation for exercise related symptoms, or abnormal resting or stress-ECG findings.

Purpose - To assess the effect of ß blockers on the occurrence of IVG, in C, with symptoms or abnormal resting or stress-ECG findings.

Methods – We repeated SE in 66 of the 101 C – (with normal echocardiogram at rest) - that developed IVG on exertion, under treatment with ß blockers. These 66 C who repeated the SE under treatment with ß blockers are the study group. 15 (23%) of them were female and the mean age of the group was 14,6 ± 1,7 years old (11 to 17).

They all underwent SE with 2D and Doppler echocardiographic evaluation of, and during treatment with ß blockers.

Results

Mean IVG in those 66 C submitted to SE was 105 ± 38 mmHg in the first SE evaluation. In SE evaluation performed under ß blockers, 37 of them didn’t develop IVG and in 29 of them IVG was significantly reduced to a mean IVG of 58 ± 32 mmHg (p< 0,0001). The mean heart rate attained at peak exercise was 178 ± 15 bpm in the first SE evaluation and 157 ± 9 bpm in the evaluation performed under treatment with ß blockers (p < 0, 0001). 47 of these C reproduced clinical symptoms (that were indication to SE) of beta-blockers, and only 7 reproduced the symptoms under treatment with beta blockers (p< 0,0001).

Conclusions

In C with symptoms, abnormal rest or exercise ECG on medical evaluation and IVG on exertion, treatment with oral ß blockers prevented the occurrence of IVG or significantly reduced its magnitude. These changes were associated to significant clinical improvement in 85 % of the symptomatic population.

Abstract P945 Figure. SE without and with beta-blockers

[Cardiac tamponade due to intrathoracic migration of a Kirschner wire.]

We report a rare case of migration of a Kirschner wire used for fixation of a multifragmentary cervical humerus fracture, causing cardiac tamponade due to main coronary artery and pulmonary injury, transversed the left upper lobe of the lung. We report on a female patient of 65 years of age, admitted to the emergency service following an accidental fall that resulted in a multifragmentary fracture of the neck of the humerus, treated surgically with percutaneous implantation of three Kirschner wires. Six days later the patient complained of chest pain radiating to the arm and back, fatigue, dyspnea and orthopnea, and was readmitted two days later in the emergency department, where chest X-ray revealed the migration of a Kirschner wire into the thoracic cavity and mediastinal widening. An echocardiogram confirmed the diagnosis of pericardial tamponade and the complementary CT scans demonstrated the Kirschner wire in the left pleural cavity.