Evaluation of Left Ventricular Volumes and Ejection Fraction from Gated Myocardial Perfusion SPECT Processed with "Myovation Evolution": Comparison of Three Automated Software Packages using Cardiac Magnetic Resonance as Reference.

BACKGROUND: The development of resolution recovery (RR) algorithms has made it possible to preserve the good quality of cardiac images despite a reduced number of counts during study acquisition. OBJECTIVE: Our purpose was to evaluate the performance of three different software packages in the quantification of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) from gated perfusion SPECT, applying a resolution recovery (RR) algorithm (GE Myovation Evolution), with respect to cardiac MRI (cMRI) as a gold standard. METHODS: We retrospectively enrolled 21 patients, with suspected or known coronary heart disease. Images at rest were reconstructed by filtered back projection (FBP) and by an iterative protocol with the RR algorithm. EDV, ESV, and LVEF were automatically computed employing Quantitative Gated SPECT (QGS), Myometrix (MX), and Corridor 4DM (4DM). Any difference in EDV, ESV, and LVEF calculation between cMRI and the three packages (with FBP and iterative reconstruction with RR) was tested using Wilcoxon or paired t-test, with the assumption of normality assessed using the Shapiro-Wilk test. Agreement between imaging reconstruction algorithms and between gated-SPECT software packages and cMRI was studied with Pearson's (r) or Spearman's (R) correlation coefficients and Lin's concordance correlation coefficient (LCC). RESULTS: Intra-software evaluation always revealed very strong correlation coefficients (R, r ≥ 0.8) and excellent LCC coefficients (LCC > 0.95), except for the LCC coefficient between MX-FBP and MX-RR in EDV evaluation, nevertheless considered very good (LCC = 0.94). EDV and ESV had significantly lower value when calculated with the RR algorithm with respect to FBP reconstruction in QGS and MX. LVEF estimation did not show significant differences for QGS-FBP, QGS-RR, MX, and 4DM-RR with respect to cMRI. CONCLUSION: All reconstruction methods systematically underestimate EDV and ESV, with higher underestimation applying only the RR. No significant differences were observed between 4DM - RR and 4DM-FBP, for each parameter, when the 4DM package was used.

Incidental Diagnosis After a Car Accident: A Rare Case of Asymptomatic Uncorrected Tetralogy of Fallot.

Tetralogy of Fallot (TOF) is a heterogeneous congenital heart disease that is occasionally diagnosed during adulthood. However, although they are often asymptomatic, adult patients with uncorrected TOF often have a poor prognosis. Poor outcomes indicate the importance of the identification and management of these patients, especially in the context of intercurrent disease or noncardiac surgery. We describe a case of clinically silent TOF in a 51-year-old woman. TOF was unmasked during a major noncardiac surgery for a polytrauma and successfully treated with the cooperation of a multidisciplinary team. (Level of Difficulty: Advanced.).

Good prognosis for pericarditis with and without myocardial involvement: results from a multicenter, prospective cohort study.

BACKGROUND: The natural history of myopericarditis/perimyocarditis is poorly known, and recently published studies have presented contrasting data on their outcomes. The aim of the present article is to assess the prognosis of myopericarditis/perimyocarditis in a multicenter, prospective cohort study. METHODS AND RESULTS: A total of 486 patients (median age, 39 years; range, 18-83 years; 300 men) with acute pericarditis or a myopericardial inflammatory syndrome (myopericarditis/perimyocarditis; 85% idiopathic, 11% connective tissue disease or inflammatory bowel disease, 5% infective) were prospectively evaluated from January 2007 to December 2011. The diagnosis of acute pericarditis was based on the presence of 2 of 4 clinical criteria (chest pain, pericardial rubs, widespread ST-segment elevation or PR depression, and new or worsening pericardial effusion). Myopericardial inflammatory involvement was suspected with atypical ECG changes for pericarditis, arrhythmias, and cardiac troponin elevation or new or worsening ventricular dysfunction on echocardiography and confirmed by cardiac magnetic resonance. After a median follow-up of 36 months, normalization of left ventricular function was achieved in >90% of patients with myopericarditis/perimyocarditis. No deaths were recorded, as well as evolution to heart failure or symptomatic left ventricular dysfunction. Recurrences (mainly as recurrent pericarditis) were the most common complication during follow-up and were recorded more frequently in patients with acute pericarditis (32%) than in those with myopericarditis (11%) or perimyocarditis (12%; P<0.001). Troponin elevation was not associated with an increase in complications. CONCLUSIONS: The outcome of myopericardial inflammatory syndromes is good. Unlike acute coronary syndromes, troponin elevation is not a negative prognostic marker in this setting.

Relationship of ECG findings to phenotypic expression in patients with hypertrophic cardiomyopathy: a cardiac magnetic resonance study.

BACKGROUND: The 12-lead electrocardiogram (ECG) is considered an essential screening tool for hypertrophic cardiomyopathy (HCM). A vast array of ECG abnormalities has been described in HCM, although their relationship to left ventricle (LV) morphology and degree of hypertrophy appears elusive. Aim of this study was to assess the relationship of ECG patterns with the HCM phenotype assessed according to the novel opportunities offered by cardiac magnetic imaging (CMR). METHODS: CMR and 12-lead ECG were performed in 257 HCM patients. Severity of ECG abnormalities was defined by the sum of 9 criteria: abnormal cardiac rhythm, QRS duration ≥ 100 ms, Romhilt-Estes score ≥ 5, fascicular block (LAHB) and/or bundle-branch block (LBBB or RBBB), ST-T abnormalities, ST-T segment elevation ≥ 0.2 mV, prolonged QTc interval, pathological Q waves, absence of normal Q wave. Four ECG groups were identified: normal (0 criteria); mildly abnormal (1-3 criteria); moderately abnormal (4-6 criteria); markedly abnormal (7-9 criteria). RESULTS: There was a direct relationship between severity of ECG abnormalities and HCM phenotype. LV mass index was normal in most patients with normal ECG and progressively increased with each class of ECG score, from 70.9 ± 18.6g/m(2) in patients with normal ECG to 107.1 ± 55.1g/m(2) among those with markedly abnormal ECG (p=<0.0001). Likewise, the prevalence and extent of late gadolinium enhancement (LGE) increased significantly with the ECG score, from 37% in patients with normal ECG to 93% in patients with markedly abnormal ECG (overall p=0.0012). A normal ECG had a negative predictive accuracy of 96% for markedly increased LV mass (>91 g/m(2) for men and >69 g/m(2) for women), and of 100% for maximum LV thickness ≥ 30 mm. CONCLUSIONS: In a large HCM cohort, the number and severity of ECG abnormalities were directly related to phenotypic expression as revealed by CMR. Although false negative ECG findings remain a challenge in population screenings for HCM, a normal ECG proved effective in ruling out severe LV hypertrophy, suggesting potential implications for long-term follow-up of HCM patients and family members. A simple score for quantification of ECG abnormalities in HCM patients is proposed.

Late gadolinium enhancement on cardiac magnetic resonance and phenotypic expression in hypertrophic cardiomyopathy.

BACKGROUND: Cardiac magnetic resonance (CMR) imaging with late gadolinium enhancement (LGE) can identify areas of myocardial fibrosis in vivo in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to examine the association between clinical-morphological variables, risk factor for sudden death, and LGE findings in a consecutive, unselected population of HCM patients. METHODS: From January 2005 to August 2009, 124 HCM patients (53 ± 17 years, 86 men) were prospectively evaluated with CMR examination, assessing left ventricular (LV) hypertrophy, function, and LGE. RESULTS: In univariate analysis, patients were divided into tertiles according to the number of segments positive for LGE (first tertile, 0.3 ± 0.4; second tertile, 2.2 ± 0.4; third tertile, 5.2 ± 1.9 segments). Male gender (P = .05), maximum LV wall thickness (P = .002), nonsustained ventricular tachycardia (P = .001), ejection fraction <50% (P = .02), LV mass (P = .02), left atrium dilation (P = .04), perfusion defects (P ≤ .001), and telesystolic volume (P = .04) were all positively related with the number of segments of LGE. In multivariable analysis, male gender (P = .007), maximum LV wall thickness (P = .006), LV mass (P = .031), and perfusion alterations (P = .017) were independent predictors of LGE extent. CONCLUSIONS: Our study shows an independent association, even at multivariate analysis, between the entity of LGE and maximum LV wall thickness, mass, and perfusion defects in patients with HCM. Whether the presence and the extent of LGE translates into clinical events later on awaits further long-term follow-up studies.

Aetiological diagnosis in acute and recurrent pericarditis: when and how.

The cause of acute and recurrent pericarditis is often a major concern for the clinicians in clinical practice. Several possible causes of pericarditis can be listed, as the pericardium may be involved in a large number of systemic disorders or may be diseased, as an isolated process. The reported diagnostic yield of extensive laboratory evaluation and pericardiocentesis is low in the absence of cardiac tamponade or suspected neoplastic, tuberculous, and purulent pericarditis. Patients with pericarditis can be safely managed on an outpatient basis without a thorough diagnostic evaluation unless a specific cause is suspected or the patient has high-risk features, or both. A targeted aetiological search should be directed to the most common cause on the basis of the clinical background, epidemiological issues or specific presentations. In developed countries the clinicians should rule out neoplastic, tuberculous, and purulent pericarditis, as well as pericarditis related to a systemic disease.

Frequency-dependent baroreflex control of blood pressure and heart rate during physical exercise.

BACKGROUND: It is widely recognised that during exercise vagal heart rate control is markedly impaired but blood pressure control may or may not be retained. We hypothesised that this uncertainty arose from the differing responses of the vagus (fast) and sympathetic (slow) arms of the autonomic effectors, and to differing sympatho-vagal balance at different exercise intensities. METHODS AND RESULTS: We studied 12 normals at rest, during moderate (50% maximal heart rate) and submaximal (80% maximal heart rate) exercise. The carotid baroreceptors were stimulated by sinusoidal neck suction at the frequency of the spontaneous high- (during moderate exercise) and low-frequency (during submaximal) fluctuations in heart period and blood pressure. The increases in these oscillations induced by neck suction were measured by autoregressive spectral analysis. At rest neck stimulation increased variability at low frequency (RR: from 6.99+/-0.24 to 8.87+/-0.18 ln-ms2; systolic pressure: from 3.05+/-1.7 to 4.09+/-0.17 ln-mm Hg2) and high frequency (RR: from 4.67+/-0.25 to 6.79+/-0.31 ln-ms2; systolic pressure: from 1.93+/-0.2 to 2.67+/-0.125 ln-mm Hg2) (all p<0.001). During submaximal exercise RR variability decreased but systolic pressure variability rose (p<0.01 vs rest); during submaximal exercise low-frequency neck stimulation increased the low-frequency fluctuations in blood pressure (2.35+/-0.51 to 4.25+/-0.38 ln-mm Hg2, p<0.05) and RR. Conversely, neck suction at high frequency was ineffective on systolic pressure, and had only minor effects on RR interval during moderate exercise. CONCLUSION: During exercise baroreflex control is active on blood pressure, but the efferent response on blood pressure and heart rate is only detected during low frequency stimulation, indicating a frequency-dependent effect.

Typical atrial flutter ablation outcome: correlation with isthmus anatomy using intracardiac echo 3D reconstruction.

AIMS: To verify if sites of conduction gaps on the isthmus correlate with anatomical peculiarities using the intracardiac echo (ICE) and a new 3D device to reconstruct the isthmus in patients undergoing cavotricuspid isthmus ablation. METHODS AND RESULTS: Twenty patients underwent isthmus ablation using an 8 mm tip ablation catheter. Two-dimensional and 3D ICE reconstruction of the isthmus was made before, during and after ablation. At the end of the lesion line isthmus block was validated by electrophysiological criteria. In case of its absence we closed the remaining conduction gaps verifying the position of the sites with ICE. Fourteen patients required a median of 8 RF pulses to obtain complete isthmus block (Group A). In the remaining 6 patients isthmus block was obtained with a median of 25 RF pulses due to conduction gaps 'resistant' to ablation (Group B). Conduction gap positions assessed by ICE were located in the central portion of the isthmus below the coronary sinus os in 71% of cases in Group A and along a prominent Eustachian ridge in Group B patients, respectively. 3D reconstruction showed a smooth isthmus in Group A with a 'peak and valleys' isthmus in Group B. In these latter patients isthmus block was obtained only after the complete ablation of the prominent Eustachian ridge. CONCLUSION: The isthmus presents anatomical variants particularly due to Eustachian ridge peculiarities which may represent a site of conduction gaps "resistant" to ablation.