[Premature ventricular complexes: what to do?] / Extrasystoles ventriculaires : que faire ?

Premature ventricular complexes (PVCs) are frequently encountered arrhythmias in the general population. They can occur in the context of an underlying structural heart disease (SHD) of ischemic, hypertensive or inflammatory cause and therefore be a prognostic factor. Some PVCs can appear in the context of inherited arrhythmic syndromes while others are seen as idiopathic in the absence of an underlying heart condition and are considered benign. Those idiopathic PVCs often arise from the ventricular outflow tracts, mostly from the right ventricle outflow tract (RVOT). The PVCs burden even with no underlying SHD can be associated with PVC-induced cardiomyopathy which is a diagnosis of exclusion.

Les extrasystoles ventriculaires (ESV) sont fréquentes dans la population générale. Elles peuvent résulter d'une cardiopathie sous-jacente d'origine ischémique, hypertensive ou inflammatoire, et représentent alors un facteur pronostique défavorable. Certaines ESV sont l'expression de syndromes arythmiques héréditaires, alors que d'autres sont qualifiées d'idiopathiques lorsqu'elles surviennent en l'absence de cardiopathie structurelle et sont généralement considérées comme bénignes. Elles prennent le plus souvent leur origine dans les chambres de chasse ventriculaires, majoritairement la chambre de chasse droite. Une charge élevée en ESV peut engendrer une cardiomyopathie rythmique avec dysfonction ventriculaire progressive en l'absence de cardiopathie structurelle. Cette entité constitue néanmoins toujours un diagnostic d'exclusion.

Deglutition-Induced Atrial Tachycardia.

While bradyarrhythmia is the most common arrhythmia during deglutition, tachycardias are considered to be a very rare condition with approximately 50 cases documented worldwide. The subjects are usually men with no structural heart disease or gastrointestinal pathology, and symptoms may vary from palpitations to lightheadedness or syncope. Management is based on adapting alimentary habits in combination with agents such as beta-blockers, calcium channel blockers, and class IA, IC, and III drugs. Radiofrequency catheter ablation offers a permanent cure in the majority of the reported cases. We report the case of a 51-year-old male with swallowing-induced palpitations, corresponding to brief episodes of atrial tachycardia. Beta-blockers and calcium channel blockers were interrupted because of intolerance. Lifestyle measures with fractionated meals allowing small boluses significantly reduced symptoms. The patient was reticent to invasive measures.

Lithium-induced ECG modifications: navigating from acute coronary syndrome to Brugada syndrome.

Lithium is frequently used in the treatment of bipolar disorders and is known to induce ECG alterations. This case study describes various patterns of lithium-induced ECG modifications in a patient with acute-on-chronic lithium intoxication. Clinicians should be familiar with this problem as it can have life-threatening consequences and lead to important changes in patient's management. Our patient was admitted for acute delirium with an ECG showing atrial fibrillation with wide QRS and ST-segment elevation. These modifications were first mistaken for an acute myocardial infarction and a diagnosis of Brugada syndrome was finally reached. Treatment after the acute phase implied changes in the therapeutic modality and required frequent monitoring.

[Pacemakers and defibrillators: what the non-specialist needs to know]. / Pacemakers et défibrillateurs: ce que le non-spécialiste doit savoir.

Cardiologists are in charge of the follow-up of patients equipped with pacemakers and defibrillators. In many situations, however, the non-specialist will have to take care of these patients. It is therefore essential that the practitioner understands the basics of how these devices work, the potential complications and the situations in which the cardiologist's intervention is necessary. This article summarizes implantation techniques, post-operative follow-up and potential complications of implantable devices. It recapitulates the differences between pacemaker, defibrillator and resynchronization therapy. It explains the stimulation modes and reminds the reader how the magnet works and the precautions to be taken in the operating theatre, during magnetic resonance imaging or in situations of emergency.

Le suivi des patients porteurs de pacemakers et de défibrillateurs incombe au cardiologue. Dans de nombreuses situations néanmoins, le non-spécialiste devra prendre en charge ces patients. Il demeure donc essentiel que le praticien soit familier avec les bases du fonctionnement de ces dispositifs, les potentielles complications et les situations pour lesquelles l'intervention du cardiologue s'avère nécessaire. Cet article résume les techniques d'implantation, le suivi postopératoire et les complications potentielles de ces dispositifs médicaux; il rappelle également les différences entre pacemaker, défibrillateur et thérapie de resynchronisation. Il revient finalement sur les modes de stimulation, le fonctionnement de l'aimant ainsi que sur les précautions à prendre au bloc opératoire, lors d'examens par résonance magnétique ou en situation d'urgence.

Case report of an unusual combination of purulent pericarditis and false aneurysm of the ascending aorta.

BACKGROUND: Purulent pericarditis is an uncommon entity, which is, in very rare cases, associated to infection of the aorta. CASE PRESENTATION: We present the case of a 42-year-old male patient, who was admitted to hospital complaining of tiredness, diarrhea and leg edema. Clinical examination revealed a hypotensive and obviously shocked patient. He was ultimately diagnosed with a rare combination of purulent pericarditis followed by false aneurysm of the ascending aorta. He was successfully treated by surgical pericardial drainage, replacement of the ascending aorta and antibiotics. CONCLUSION: Mycotic aneurysms can rarely be associated with purulent pericarditis. Our literature review shows that there are two mechanisms explaining this association and that in most of the published cases infective endocarditis could not be demonstrated.

Performance of highly sensitive cardiac troponin T assay to detect ischaemia at PET-CT in low-risk patients with acute coronary syndrome: a prospective observational study.

BACKGROUND: Highly sensitive troponin T (hs-TnT) assay has improved clinical decision-making for patients admitted with chest pain. However, this assay's performance in detecting myocardial ischaemia in a lowrisk population has been poorly documented. PURPOSE: To assess hs-TnT assay's performance to detect myocardial ischaemia at positron emission tomography/CT (PET-CT) in low-risk patients admitted with chest pain. METHODS: Patients admitted for chest pain with a nonconclusive ECG and negative standard cardiac troponin T results at admission and after 6 hours were prospectively enrolled. Their hs-TnT samples were at T0, T2 and T6. Physicians were blinded to hs-TnT results. All patients underwent a PET-CT at rest and during adenosine-induced stress. All patients with a positive PET-CT result underwent a coronary angiography. RESULTS: Forty-eight patients were included. Six had ischaemia at PET-CT. All of them had ≥1 significant stenosis at coronary angiography. Areas under the curve (95% CI) for predicting significant ischaemia at PET-CT using hs-TnT were 0.764 (0.515 to 1.000) at T0, 0.812(0.616 to 1.000) at T2 and 0.813(0.638 to 0.989) at T6. The receiver operating characteristicbased optimal cut-off value for hs-TnT at T0, T2 and T6 needed to exclude significant ischaemia at PET-CT was <4 ng/L. Using this value, sensitivity, specificity, positive and negative predictive values of hs-TnT to predict significant ischaemia were 83%/38%/16%/94% at T0, 100%/40%/19%/100% at T2 and 100%/43%/20%/100% at T6, respectively. CONCLUSIONS: Our findings suggest that in low-risk patients, using the hs-TnT assay with a cut-off value of 4 ng/L demonstrates excellent negative predictive value to exclude myocardial ischaemia detection at PET-CT, at the expense of weak specificity and positive predictive value. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT01374607.

Assessment of quality performance measures for primary percutaneous coronary intervention: A report from a tertiary referral centre in Switzerland.

AIMS: The present study aimed to document a local pattern of care in consecutive patients undergoing primary percutaneous coronary intervention for ST-elevation myocardial infarction (STEMI) in a tertiary centre in Switzerland. METHODS: A retrospective study was conducted at the University Hospital of Lausanne, Switzerland. A total of 389 consecutive patients undergoing primary percutaneous coronary intervention for STEMI between 2009 and 2010 were studied. The audit focused on 14 items derived from the American College of Cardiology/American Heart Association 2008 quality performance measures position paper on STEMI management. These indicators all corresponded to a class 1 recommendation at the time of the study period. RESULTS: All patients received aspirin and anticoagulation within 24 hours after admission. Only 31.3% of patients received beta-blocking agents within 24 hours of admission. Left ventricular function was evaluated in 89.2% of cases and referral for cardiac rehabilitation was achieved in 78.5% of eligible patients. Patients subsequently transferred to another facility for further inpatient care had significantly less evaluation of left ventricular function (82.0% vs. 97.5%, P<0.0001). Global adherence to all performance measures was significantly higher among younger patients (45.9% vs. 31.4%, P<0.0075). CONCLUSIONS: The present study, which provides a snapshot on quality performance between 2009 and 2010 in a referral centre for primary percutaneous coronary intervention, demonstrates a suboptimal application of the global guidelines on STEMI management. This observation is mainly driven by a low prescription of beta-blocking agents, a class IA indication at that time. This observation should be put in perspective to current practice.

Relationship between time of day and periprocedural myocardial infarction after elective angioplasty.

OBJECTIVES: To test if the time of day significantly influences the occurrence of type 4A myocardial infarction in elective patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: Recent studies have suggested an influence of circadian rhythms on myocardial infarction size and mortality among patients with ST-elevation myocardial infarction. The aim of the study is to investigate whether periprocedural myocardial infarction (PMI) is influenced by the time of day in elective patients undergoing PCI. METHODS: All consecutive patients undergoing elective PCI between 2007 and 2011 at our institutions with known post-interventional troponin were retrospectively included. Patients (n = 1021) were divided into two groups according to the starting time of the PCI: the morning group (n = 651) between 07:00 and 11:59, and the afternoon group (n = 370) between 12:00 and 18:59. Baseline and procedural characteristics as well as clinical outcome defined as the occurrence of PMI were compared between groups. In order to limit selection bias, all analyses were equally performed in 308 pairs using propensity score (PS) matching. RESULTS: In the overall population, the rate of PMI was statistically lower in the morning group compared to the afternoon group (20% vs. 30%, p < 0.001). This difference remained statistically significant after PS-matching (21% vs. 29%, p = 0.03). Multivariate analysis shows that being treated in the afternoon independently increases the risk for PMI with an odds ratio of 2.0 (95%CI: 1.1-3.4; p = 0.02). CONCLUSIONS: This observational PS-matched study suggests that the timing of an elective PCI influences the rate of PMI.

Association of biomarkers of lipid modification with functional and morphological indices of coronary stenosis severity in stable coronary artery disease.

Biomarkers of blood lipid modification and oxidative stress have been associated with increased cardiovascular morbidity. We sought to determine whether these biomarkers were related to functional indices of stenosis severity among patients with stable coronary artery disease. We studied 197 consecutive patients with stable coronary artery disease due to single vessel disease. Fractional flow reserve (FFR) ≤ 0.80 was assessed as index of a functionally significant lesion. Serum levels of secretory phospholipase A2 (sPLA2) activity, secretory phospholipase A2 type IIA (sPLA2-IIA), myeloperoxydase (MPO), lipoprotein-associated phospholipase A2 (Lp-PLA2), and oxidized low-density lipoprotein (OxLDL) were assessed using commercially available assays. Patients with FFR > 0.8 had higher sPLA2 activity, sPLA2 IIA, and OxLDL levels than patients with FFR ≤ 0.8 (21.25 [16.03-27.28] vs 25.85 [20.58-34.63] U/mL, p < 0.001, 2.0 [1.5-3.4] vs 2.6 [2.0-3.4] ng/mL, p < 0.01; and 53.0 [36.0-71.0] vs 64.5 [50-89.25], p < 0.001 respectively). Patients with FFR > 0.80 had similar Lp-PLA2 and MPO levels versus those with FFR ≤ 0.8. sPLA2 activity, sPLA2 IIA significantly increased area under the curve over baseline characteristics to predict FFR ≤ 0.8 (0.67 to 0.77 (95 % confidence interval [CI]: 0.69-0.85) p < 0.01 and 0.67 to 0.77 (95 % CI: 0.69-0.84) p < 0.01, respectively). Serum sPLA2 activity as well as sPLA2-IIA level is related to functional characteristics of coronary stenoses in patients with stable coronary artery disease.

Myocardial no-reflow treatment.

No-reflow phenomenon is a consequence of percutaneous coronary intervention (PCI) which arises most of the time in the setting of myocardial infarction, but can be also the consequence of PCI in stable angina patients (rotatablator ablation technique or angioplasty in saphenous vein grafts). In this review, we summarize two ways of treating the no-reflow according to the current literature. First through the pharmacological approach where several compounds have been assessed like adenosine, nitroprusside, verapamil, nicorandil, dipyridamole, epinephrine or cyclosporine. Second through the mechanical approach where few strategies have been examined like intra-aortic balloon pumping or postconditioning. Finally, we provide an algorithm for treating a no-reflow even though no studies showed a beneficial effect in terms of clinical endpoints.

St. John's Wort in patients non-responders to clopidogrel undergoing percutaneous coronary intervention: a single-center randomized open-label trial (St. John's Trial).

We assessed if St. John's Wort (SJW) improves platelet response in patients (pts) resistant to clopidogrel after percutaneous coronary intervention (PCI). Stable angina pts non-responders to 600 mg clopidogrel (P2Y12 reaction units (PRU) >240) were randomized (2:1) to SJW (n = 15) or placebo (n = 8). SJW (300 mg × 3/day) was administrated for 2 weeks after PCI. Platelet reactivity was assessed by VerifyNowTM before (BL), 2 (T1), and 4 weeks (T2) after PCI. PRU significantly changed during protocol in SJW (BL (316 ± 60) vs. T1 (170 ± 87) vs. T2 (220 ± 96), p < 0.0001) and placebo group (BL (288 ± 36) vs. T1 (236 ± 31) vs. T2 (236 ± 62), p = 0.046). Yet, PRU changes from BL were higher at T1 in SJW than in placebo group (Δ%, -47 ± 24 vs. -16 ± 15, p = 0.0033), with no differences at T2 between the groups (Δ%, -30 ± 29 vs. -17 ± 24, p = 0.30). Residual platelet reactivity improved with SJW during the first month post-PCI.

Pressure-diameter relationship in human coronary arteries.

BACKGROUND: To quantify the changes in arterial dimensions after the acute changes in pressure associated with percutaneous coronary intervention (PCI). METHODS AND RESULTS: Forty-eight patients with one angiographically moderate-to-severe stenosis were included in the study. The pressure proximal and distal to the stenosis and the arterial diameter proximal and distal to the stenosis were measured at baseline, after intracoronary nitrates, and after stent PCI. In addition, in 8 patients distal pressure and coronary diameter were assessed while graded, controlled stenoses were created in the stented segment by progressive inflation of a balloon catheter. The mean diameter of the proximal coronary segment was 2.75 ± 0.08 mm, 2.92 ± 0.08 mm (+7.4%), and 3.10 ± 0.07 mm (+14.7%) at baseline, after nitrates and after PCI, respectively (P<0.001). The mean diameter of the distal coronary segment was 2.07 ± 0.09 mm, 2.23 ± 0.09 mm (+9.7%), and 2.5±0.07 mm (+28.4%) at baseline, after nitrates and after PCI, respectively (P<0.001). The increase in distal diameter correlated significantly with the increase in distal pressure after PCI (r(2)=0.57; P<0.001). When graded stenoses were created, a decrease in diameter of 18 ± 4% was observed with a pressure drop of 43 ± 5 mm Hg. CONCLUSIONS: The diameter of coronary arteries markedly varies with their distending pressure. After re-establishment of a normal distending pressure by stenting of severe coronary stenoses, a proportional increase in vessel diameter is observed. This should be taken into account when choosing the stent diameter and is an argument to discourage direct stenting.

Circadian variations of ischemic burden among patients with myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: Several parameters of cardiovascular physiology and pathophysiology exhibit circadian rhythms. Recently, a relation between infarct size and the time of day at which it occurs has been suggested in experimental models of myocardial infarction. The aim of this study is to investigate whether circadian rhythms could cause differences in ischemic burden in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). METHODS: In 353 consecutive patients with STEMI treated by PPCI, time of symptom onset, peak creatine kinase (CK), and follow-up at 30 days were obtained. We divided 24 hours into 4 time groups based on time of symptom onset (00:00-05:59, 06:00-11:59, 12:00-17:59, and 18:00-23:59). RESULTS: There was no difference between the groups regarding baseline patients and management's characteristics. At multivariable analysis, there was a statistically significant difference between peak CK levels among patients with symptom onset between 00:00 and 05:59 when compared with peak CK levels of patients with symptom onset in any other time group (mean increase 38.4%, P < .05). Thirty-day mortality for STEMI patients with symptom onset occurring between 00:00 and 05:59 was significantly higher than any other time group (P < .05). CONCLUSION: This study demonstrates an independent correlation between the infarct size of STEMI patients treated by PPCI and the time of the day at which symptoms occurred. These results suggest that time of the day should be a critical issue to look at when assessing prognosis of patients with myocardial infarction.

Long-term follow-up after fractional flow reserve-guided treatment strategy in patients with an isolated proximal left anterior descending coronary artery stenosis.

OBJECTIVES: This study sought to evaluate the long-term clinical outcome of patients with an angiographically intermediate left anterior descending coronary artery (LAD) stenosis in whom the revascularization strategy was based on fractional flow reserve (FFR). BACKGROUND: When revascularization is based mainly on angiographic guidance, a number of hemodynamically nonsignificant stenoses will be revascularized. METHODS: In 730 patients with a 30% to 70% isolated stenosis in the proximal LAD and no significant valvular disease, FFR measurements were obtained to guide treatment strategy. When FFR was ≥ 0.80, the patients (n = 564) were treated medically (medical group); when FFR was <0.80, the patients (n = 166) underwent a revascularization procedure (revascularization group; 13% coronary artery bypass graft surgery and 87% percutaneous coronary intervention). A 100% long-term clinical follow-up (median follow-up: 40 months) was obtained. The 5-year survival of the medical group was compared with that of a reference population. For each patient, 4 controls were selected from an age- and sex-matched control population. RESULTS: The 5-year survival estimate was 92.9% in the medical group versus 89.6% in the controls (p = 0.74). The mean diameter stenosis was significantly smaller in the medical than in the revascularization group (39 ± 14% vs. 54 ± 13%, p < 0.0001), but there was a large overlap between both groups. The 5-year event-free survival estimates (death, myocardial infarction, and target vessel revascularization) were 89.7% and 68.5%, respectively (p < 0.0001). CONCLUSIONS: Medical treatment of patients with a hemodynamically nonsignificant stenosis (FFR ≥ 0.80) in the proximal LAD is associated with an excellent long-term clinical outcome with survival at 5 years similar to an age- and sex-matched control population.

Transcriptional fingerprint of human whole blood at the site of coronary occlusion in acute myocardial infarction.

AIMS: Transcriptome patterns associated with acute myocardial infarction at the site of coronary occlusion are largely unknown. The aim of this study was to decipher the angiogenic, atherosclerotic, and inflammatory mRNA profiles in whole blood samples collected at the site of coronary occlusion in patients with ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: In five consecutive patients with STEMI, blood was sampled at the site of occlusion (local) and in the systemic circulation (peripheral) during primary percutaneous coronary intervention. RNA was extracted from whole blood samples. Among 221 genes involved in angiogenesis, inflammation and atherosclerosis, 24 were shown to be differentially modulated locally, by analysis with custom-designed DNA array technology. Validation in 28 distinct STEMI patients using real-time quantitative PCR identified seven out of these 24 genes to be consistently and significantly upregulated in local versus peripheral blood (p<0.05). Three genes were chemokine family members (CCL2, CCL18 and CXCL12), three genes belonged to the cell-cell and cell-extracellular matrix family (FN1, CDH5 and SPP1), and one gene was representative of the lipoprotein family (APOE). CONCLUSIONS: We identified a set of whole blood transcripts induced at the site of coronary occlusion in the acute phase of myocardial infarction. Resolved genes indicate a predominant role for chemokines, cell-extracellular matrix, and lipoprotein alterations in the pathophysiology of acute myocardial infarction and the initial response to myocardial injury.

Relationship between peripheral arterial reactive hyperemia and residual platelet reactivity after 600 mg clopidogrel.

Clopidogrel reduces long-term ischemic events in patients with acute coronary syndrome or stable angina (SA) undergoing percutaneous coronary intervention (PCI). Endothelial function improvement has been proposed, among other factors, for this beneficial effect of clopidogrel, but whether this might be associated to its anti-platelet action remains unclear. We tested the hypothesis that clopidogrel improvement of peripheral vascular endothelial function might be associated with inhibition of platelet aggregation. Endothelial function was evaluated before and at least 12 h after 600 mg clopidogrel in 43 SA pts undergoing elective PCI by: (a) reactive hyperemia peripheral arterial tonometry (measuring the Endoscore); (b) circulating endothelial microparticles (EMPs). Response to clopidogrel was measured with point-of-care VerifyNow P2Y12 assay and expressed as platelet reaction unit (PRU) and percent platelet inhibition (%PI). High platelet reactivity after clopidogrel was defined as PRU ≥ 240. Endothelial function improved after clopidogrel in 20 pts. Changes in Endoscore (Δ Endoscore) were significantly correlated with both PRU (r = -0.61, P < 0.001) and %PI (r = 0.57, P < 0.001). Endoscore significantly increased after clopidogrel in pts with PRU < 240 (0.38 ± 0.26 to 0.57 ± 0.33, P < 0.001), but did not in pts with PRU ≥ 240 (0.53 ± 0.31 to 0.40 ± 0.37, P = 0.12). EMPs were also significantly reduced in pts with PRU < 240 (222 [140-593] to 142 [83-371]/µl, P = 0.001), while no changes were observed in pts with PRU ≥ 240 (256 [178-531] to 388 [238-499]/µl, P = 0.55). In patients with stable coronary artery disease, a single 600 mg clopidogrel loading dose improves vascular endothelial function. This improvement is associated with optimal platelet inhibition and it is not observed in patients with post-clopidogrel high platelet reactivity.

Translesional pressure gradients to predict blood pressure response after renal artery stenting in patients with renovascular hypertension.

BACKGROUND: In previous studies on the effect of renal stenting on arterial hypertension, patients were selected mainly on the basis of angiographic parameters of the renal artery stenosis. The aim of the present study was to evaluate whether translesional pressure gradients could identify the patients with renal artery stenosis who might benefit from stenting. METHODS AND RESULTS: A total of 53 consecutive hypertensive patients with unilateral RAS scheduled for renal artery intervention were recruited. Transstenotic pressure gradients were measured at baseline and during maximal hyperemia, before renal artery stenting. Twenty-four-hour ambulatory blood pressure measurements were performed in all patients before and 3 months after the intervention. Average reductions in systolic blood pressure and diastolic blood pressure at follow-up were -20±30 mm Hg and -2±12 mm Hg, respectively. At multivariate analysis, dopamine-induced mean gradient was the only independent predictor of the variations of both systolic blood pressure (regression coefficient=-4.03, standard error=1.11; P<0.001) and diastolic blood pressure (regression coefficient=-3.11, standard error=1.20; P=0.009). Patients who showed a decline in systolic blood pressure from the baseline value >20 mm Hg were considered as "responders." The optimal cutoff for identification of "responders" was a dopamine-induced mean gradient ≥20 mm Hg (area under the curve, 0.77; 95% confidence interval, 0.64 to 0.90; P=0.001). CONCLUSIONS: A dopamine-induced mean pressure gradient of ≥20 mm Hg is highly predictive of arterial hypertension improvement after renal stenting, and therefore this measurement is useful for appropriate selection of patients with arterial hypertension.